Drupal 8.0.0 beta 12. More info: https://www.drupal.org/node/2514176

core/modules/block/block.api.php

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+<?php
+
+/**
+ * @file
+ * Hooks provided by the Block module.
+ */
+
+use Drupal\Core\Access\AccessResult;
+
+/**
+ * @defgroup block_api Block API
+ * @{
+ * Information about the classes and interfaces that make up the Block API.
+ *
+ * Blocks are a combination of a configuration entity and a plugin. The
+ * configuration entity stores placement information (theme, region, weight) and
+ * any other configuration that is specific to the block. The block plugin does
+ * the work of rendering the block's content for display.
+ *
+ * To define a block in a module you need to:
+ * - Define a Block plugin by creating a new class that implements the
+ *   \Drupal\Core\Block\BlockPluginInterface, in namespace Plugin\Block under your
+ *   module namespace. For more information about creating plugins, see the
+ *   @link plugin_api Plugin API topic. @endlink
+ * - Usually you will want to extend the \Drupal\Core\Block\BlockBase class, which
+ *   provides a common configuration form and utility methods for getting and
+ *   setting configuration in the block configuration entity.
+ * - Block plugins use the annotations defined by
+ *   \Drupal\Core\Block\Annotation\Block. See the
+ *   @link annotation Annotations topic @endlink for more information about
+ *   annotations.
+ *
+ * The Block API also makes use of Condition plugins, for conditional block
+ * placement. Condition plugins have interface
+ * \Drupal\Core\Condition\ConditionInterface, base class
+ * \Drupal\Core\Condition\ConditionPluginBase, and go in plugin namespace
+ * Plugin\Condition. Again, see the Plugin API and Annotations topics for
+ * details of how to create a plugin class and annotate it.
+ *
+ * There are also several block-related hooks, which allow you to affect
+ * the content and access permissions for blocks:
+ * - hook_block_view_alter()
+ * - hook_block_view_BASE_BLOCK_ID_alter()
+ * - hook_block_access()
+ *
+ * Further information and examples:
+ * - \Drupal\system\Plugin\Block\SystemPoweredByBlock provides a simple example
+ *   of defining a block.
+ * - \Drupal\user\Plugin\Condition\UserRole is a straightforward example of a
+ *   block placement condition plugin.
+ * - \Drupal\book\Plugin\Block\BookNavigationBlock is an example of a block with
+ *   a custom configuration form.
+ * - For a more in-depth discussion of the Block API, see
+ *   https://www.drupal.org/developing/api/8/block_api.
+ * - The Examples for Developers project also provides a Block example in
+ *   https://www.drupal.org/project/examples.
+ * @}
+ */
+
+/**
+ * @addtogroup hooks
+ * @{
+ */
+
+/**
+ * Alter the result of \Drupal\Core\Block\BlockBase::build().
+ *
+ * This hook is called after the content has been assembled in a structured
+ * array and may be used for doing processing which requires that the complete
+ * block content structure has been built.
+ *
+ * If the module wishes to act on the rendered HTML of the block rather than
+ * the structured content array, it may use this hook to add a #post_render
+ * callback. Alternatively, it could also implement hook_preprocess_HOOK() for
+ * block.html.twig. See drupal_render() documentation or the
+ * @link themeable Default theme implementations topic @endlink for details.
+ *
+ * In addition to hook_block_view_alter(), which is called for all blocks, there
+ * is hook_block_view_BASE_BLOCK_ID_alter(), which can be used to target a
+ * specific block or set of similar blocks.
+ *
+ * @param array &$build
+ *   A renderable array of data, as returned from the build() implementation of
+ *   the plugin that defined the block:
+ *   - #title: The default localized title of the block.
+ * @param \Drupal\Core\Block\BlockPluginInterface $block
+ *   The block plugin instance.
+ *
+ * @see hook_block_view_BASE_BLOCK_ID_alter()
+ * @see entity_crud
+ *
+ * @ingroup block_api
+ */
+function hook_block_view_alter(array &$build, \Drupal\Core\Block\BlockPluginInterface $block) {
+  // Remove the contextual links on all blocks that provide them.
+  if (isset($build['#contextual_links'])) {
+    unset($build['#contextual_links']);
+  }
+}
+
+/**
+ * Provide a block plugin specific block_view alteration.
+ *
+ * In this hook name, BASE_BLOCK_ID refers to the block implementation's plugin
+ * id, regardless of whether the plugin supports derivatives. For example, for
+ * the \Drupal\system\Plugin\Block\SystemPoweredByBlock block, this would be
+ * 'system_powered_by_block' as per that class's annotation. And for the
+ * \Drupal\system\Plugin\Block\SystemMenuBlock block, it would be
+ * 'system_menu_block' as per that class's annotation, regardless of which menu
+ * the derived block is for.
+ *
+ * @param array $build
+ *   A renderable array of data, as returned from the build() implementation of
+ *   the plugin that defined the block:
+ *   - #title: The default localized title of the block.
+ * @param \Drupal\Core\Block\BlockPluginInterface $block
+ *   The block plugin instance.
+ *
+ * @see hook_block_view_alter()
+ * @see entity_crud
+ *
+ * @ingroup block_api
+ */
+function hook_block_view_BASE_BLOCK_ID_alter(array &$build, \Drupal\Core\Block\BlockPluginInterface $block) {
+  // Change the title of the specific block.
+  $build['#title'] = t('New title of the block');
+}
+
+/**
+ * Control access to a block instance.
+ *
+ * Modules may implement this hook if they want to have a say in whether or not
+ * a given user has access to perform a given operation on a block instance.
+ *
+ * @param \Drupal\block\Entity\Block $block
+ *   The block instance.
+ * @param string $operation
+ *   The operation to be performed, e.g., 'view', 'create', 'delete', 'update'.
+ * @param \Drupal\user\Entity\User $account
+ *   The user object to perform the access check operation on.
+ * @param string $langcode
+ *   The language code to perform the access check operation on.
+ *
+ * @return \Drupal\Core\Access\AccessResultInterface
+ *   The access result. If all implementations of this hook return
+ *   AccessResultInterface objects whose value is !isAllowed() and
+ *   !isForbidden(), then default access rules from
+ *   \Drupal\block\BlockAccessControlHandler::checkAccess() are used.
+ *
+ * @see \Drupal\Core\Entity\EntityAccessControlHandler::access()
+ * @see \Drupal\block\BlockAccessControlHandler::checkAccess()
+ * @ingroup block_api
+ */
+function hook_block_access(\Drupal\block\Entity\Block $block, $operation, \Drupal\user\Entity\User $account, $langcode) {
+  // Example code that would prevent displaying the 'Powered by Drupal' block in
+  // a region different than the footer.
+  if ($operation == 'view' && $block->getPluginId() == 'system_powered_by_block') {
+    return AccessResult::forbiddenIf($block->getRegion() != 'footer')->cacheUntilEntityChanges($block);
+  }
+
+  // No opinion.
+  return AccessResult::neutral();
+}
+
+/**
+ * @} End of "addtogroup hooks".
+ */

core/modules/block/block.info.yml

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+name: Block
+type: module
+description: 'Controls the visual building blocks a page is constructed with. Blocks are boxes of content rendered into an area, or region, of a web page.'
+package: Core
+version: VERSION
+core: 8.x
+configure: block.admin_display

core/modules/block/block.libraries.yml

@@ -0,0 +1,19 @@
+drupal.block:
+  version: VERSION
+  js:
+    js/block.js: {}
+  dependencies:
+    - core/jquery
+    - core/drupal
+
+drupal.block.admin:
+  version: VERSION
+  js:
+    js/block.admin.js: {}
+  css:
+    theme:
+      css/block.admin.css: {}
+  dependencies:
+    - core/jquery
+    - core/drupal
+    - core/drupal.ajax

core/modules/block/block.links.contextual.yml

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+block_configure:
+  title: 'Configure block'
+  route_name: 'entity.block.edit_form'
+  group: 'block'

core/modules/block/block.links.menu.yml

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+block.admin_display:
+  title: 'Block layout'
+  parent: system.admin_structure
+  description: 'Configure what block content appears in your site''s sidebars and other regions.'
+  route_name: block.admin_display

core/modules/block/block.links.task.yml

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+entity.block.edit_form:
+  title: 'Configure block'
+  route_name: entity.block.edit_form
+  base_route: entity.block.edit_form
+
+# Per theme block layout pages.
+block.admin_display:
+  title: 'Block layout'
+  route_name: block.admin_display
+  base_route: block.admin_display
+block.admin_display_theme:
+  title: 'Block layout'
+  route_name: block.admin_display_theme
+  parent_id: block.admin_display
+  deriver: 'Drupal\block\Plugin\Derivative\ThemeLocalTask'

core/modules/block/block.module

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+<?php
+
+/**
+ * @file
+ * Controls the visual building blocks a page is constructed with.
+ */
+
+use Drupal\block\BlockInterface;
+use Drupal\Component\Utility\Html;
+use Drupal\Core\Cache\Cache;
+use Drupal\Core\Routing\RouteMatchInterface;
+use Drupal\Core\Url;
+use Drupal\language\ConfigurableLanguageInterface;
+use Drupal\system\Entity\Menu;
+use Drupal\block\Entity\Block;
+
+/**
+ * Implements hook_help().
+ */
+function block_help($route_name, RouteMatchInterface $route_match) {
+  switch ($route_name) {
+    case 'help.page.block':
+      $block_content = \Drupal::moduleHandler()->moduleExists('block_content') ? \Drupal::url('help.page', array('name' => 'block_content')) : '#';
+      $output = '';
+      $output .= '<h3>' . t('About') . '</h3>';
+      $output .= '<p>' . t('The Block module allows you to place blocks in regions of your installed themes, and configure block settings. For more information, see the <a href="!blocks-documentation">online documentation for the Block module</a>.', array('!blocks-documentation' => 'https://www.drupal.org/documentation/modules/block/')) . '</p>';
+      $output .= '<h3>' . t('Uses') . '</h3>';
+      $output .= '<dl>';
+      $output .= '<dt>' . t('Placing and moving blocks') . '</dt>';
+      $output .= '<dd>' . t('You can place a new block by clicking on its title in the <em>Place blocks</em> list on the <a href="!blocks">Block layout page</a> and choosing a region to place it in. Once a block is placed, it can be moved to a different region by dragging or using the drop-down <em>Region</em> list, and then clicking <em>Save blocks</em>.', array('!blocks' => \Drupal::url('block.admin_display'))) . '</dd>';
+      $output .= '<dt>' . t('Toggling between different themes') . '</dt>';
+      $output .= '<dd>' . t('Blocks are placed and configured specifically for each theme. The Block layout page opens with the default theme, but you can toggle to other installed themes.') . '</dd>';
+      $output .= '<dt>' . t('Demonstrating block regions for a theme') . '</dt>';
+      $output .= '<dd>' . t('You can see where the regions are for the current theme by clicking the <em>Demonstrate block regions</em> link on the <a href="!blocks">Block layout page</a>. Regions are specific to each theme.', array('!blocks' => \Drupal::url('block.admin_display'))) . '</dd>';
+      $output .= '<dt>' . t('Configuring block settings') . '</dt>';
+      $output .= '<dd>' . t('To change the settings of an individual block click on the <em>Configure</em> link on the <a href="!blocks">Block layout page</a>. The available options vary depending on the module that provides the block. For all blocks you can change the block title and toggle whether to display it.', array('!blocks' => Drupal::url('block.admin_display'))) . '</dd>';
+      $output .= '<dt>' . t('Controlling visibility') . '</dt>';
+      $output .= '<dd>' . t('You can control the visibility of a block by restricting it to specific pages, content types, and/or roles by setting the appropriate options under <em>Visibility settings</em> of the block configuration.') . '</dd>';
+      $output .= '<dt>' . t('Adding custom blocks') . '</dt>';
+      $output .= '<dd>' . t('You can add custom blocks, if the <em>Custom Block</em> module is installed. For more information, see the <a href="!blockcontent-help">Custom Block help page</a>.', array('!blockcontent-help' => $block_content)) . '</dd>';
+      $output .= '</dl>';
+      return $output;
+  }
+  if ($route_name == 'block.admin_display' || $route_name == 'block.admin_display_theme') {
+    $demo_theme = $route_match->getParameter('theme') ?: \Drupal::config('system.theme')->get('default');
+    $themes = \Drupal::service('theme_handler')->listInfo();
+    $output = '<p>' . t('This page provides a drag-and-drop interface for adding a block to a region, and for controlling the order of blocks within regions. To add a block to a region, or to configure its specific title and visibility settings, click the block title under <em>Place blocks</em>. Since not all themes implement the same regions, or display regions in the same way, blocks are positioned on a per-theme basis. Remember that your changes will not be saved until you click the <em>Save blocks</em> button at the bottom of the page.') . '</p>';
+    $output .= '<p>' . \Drupal::l(t('Demonstrate block regions (@theme)', array('@theme' => $themes[$demo_theme]->info['name'])), new Url('block.admin_demo', array('theme' => $demo_theme))) . '</p>';
+    return $output;
+  }
+}
+
+/**
+ * Implements hook_theme().
+ */
+function block_theme() {
+  return array(
+    'block' => array(
+      'render element' => 'elements',
+    ),
+    'block_list' => array(
+      'render element' => 'form',
+    ),
+  );
+}
+
+/**
+ * Implements hook_page_top().
+ */
+function block_page_top(array &$page_top) {
+  if (\Drupal::routeMatch()->getRouteName() === 'block.admin_demo') {
+    $theme = \Drupal::theme()->getActiveTheme()->getName();
+    $page_top['backlink'] = array(
+      '#type' => 'link',
+      '#title' => t('Exit block region demonstration'),
+      '#options' => array('attributes' => array('class' => array('block-demo-backlink'))),
+      '#weight' => -10,
+    );
+    if (\Drupal::config('system.theme')->get('default') == $theme) {
+      $page_top['backlink']['#url'] = Url::fromRoute('block.admin_display');
+    }
+    else {
+      $page_top['backlink']['#url'] = Url::fromRoute('block.admin_display_theme', ['theme' => $theme]);
+    }
+  }
+}
+
+/**
+ * Returns an array of block class instances by theme.
+ *
+ * @param $theme
+ *   The theme to rehash blocks for. If not provided, defaults to the currently
+ *   used theme.
+ *
+ * @return
+ *   Blocks currently exported by modules.
+ */
+function _block_rehash($theme = NULL) {
+  $theme = $theme ? $theme : \Drupal::config('system.theme')->get('default');
+  $regions = system_region_list($theme);
+  $blocks = entity_load_multiple_by_properties('block', array('theme' => $theme));
+  foreach ($blocks as $block_id => $block) {
+    // Remove any invalid block from the list.
+    // @todo Remove this check as part of https://www.drupal.org/node/1776830.
+    if (!$block->getPlugin()) {
+      unset($blocks[$block_id]);
+      continue;
+    }
+    $region = $block->getRegion();
+    $status = $block->status();
+    // Disable blocks in invalid regions.
+    if (!empty($region) && $region != BlockInterface::BLOCK_REGION_NONE && !isset($regions[$region]) && $status) {
+      drupal_set_message(t('The block %info was assigned to the invalid region %region and has been disabled.', array('%info' => $block_id, '%region' => $region)), 'warning');
+      // Disabled blocks are moved into the BlockInterface::BLOCK_REGION_NONE
+      // later so no need to move the block to another region.
+      $block->disable()->save();
+    }
+    // Set region to none if not enabled.
+    if (!$status && $region != BlockInterface::BLOCK_REGION_NONE) {
+      $block->setRegion(BlockInterface::BLOCK_REGION_NONE);
+      $block->save();
+    }
+  }
+  return $blocks;
+}
+
+/**
+ * Initializes blocks for installed themes.
+ *
+ * @param $theme_list
+ *   An array of theme names.
+ */
+function block_themes_installed($theme_list) {
+  foreach ($theme_list as $theme) {
+    block_theme_initialize($theme);
+  }
+}
+
+/**
+ * Assigns an initial, default set of blocks for a theme.
+ *
+ * This function is called the first time a new theme is installed. The new
+ * theme gets a copy of the default theme's blocks, with the difference that if
+ * a particular region isn't available in the new theme, the block is assigned
+ * to the new theme's default region.
+ *
+ * @param $theme
+ *   The name of a theme.
+ */
+function block_theme_initialize($theme) {
+  // Initialize theme's blocks if none already registered.
+  $has_blocks = entity_load_multiple_by_properties('block', array('theme' => $theme));
+  if (!$has_blocks) {
+    $default_theme = \Drupal::config('system.theme')->get('default');
+    // Apply only to new theme's visible regions.
+    $regions = system_region_list($theme, REGIONS_VISIBLE);
+    $default_theme_blocks = entity_load_multiple_by_properties('block', array('theme' => $default_theme));
+    foreach ($default_theme_blocks as $default_theme_block_id => $default_theme_block) {
+      if (strpos($default_theme_block_id, $default_theme . '_') === 0) {
+        $id = str_replace($default_theme, $theme, $default_theme_block_id);
+      }
+      else {
+        $id = $theme . '_' . $default_theme_block_id;
+      }
+      $block = $default_theme_block->createDuplicateBlock($id, $theme);
+      // If the region isn't supported by the theme, assign the block to the
+      // theme's default region.
+      if (!isset($regions[$block->getRegion()])) {
+        $block->setRegion(system_default_region($theme));
+      }
+      $block->save();
+    }
+  }
+}
+
+/**
+ * Implements hook_rebuild().
+ */
+function block_rebuild() {
+  foreach (\Drupal::service('theme_handler')->listInfo() as $name => $data) {
+    if ($data->status) {
+      _block_rehash($name);
+    }
+  }
+}
+
+/**
+ * Implements hook_theme_suggestions_HOOK().
+ */
+function block_theme_suggestions_block(array $variables) {
+  $suggestions = array();
+
+  $suggestions[] = 'block__' . $variables['elements']['#configuration']['provider'];
+  // Hyphens (-) and underscores (_) play a special role in theme suggestions.
+  // Theme suggestions should only contain underscores, because within
+  // drupal_find_theme_templates(), underscores are converted to hyphens to
+  // match template file names, and then converted back to underscores to match
+  // pre-processing and other function names. So if your theme suggestion
+  // contains a hyphen, it will end up as an underscore after this conversion,
+  // and your function names won't be recognized. So, we need to convert
+  // hyphens to underscores in block deltas for the theme suggestions.
+
+  // We can safely explode on : because we know the Block plugin type manager
+  // enforces that delimiter for all derivatives.
+  $parts = explode(':', $variables['elements']['#plugin_id']);
+  $suggestion = 'block';
+  while ($part = array_shift($parts)) {
+    $suggestions[] = $suggestion .= '__' . strtr($part, '-', '_');
+  }
+
+  if (!empty($variables['elements']['#id'])) {
+    $suggestions[] = 'block__' . $variables['elements']['#id'];
+  }
+
+  return $suggestions;
+}
+
+/**
+ * Prepares variables for block templates.
+ *
+ * Default template: block.html.twig.
+ *
+ * Prepares the values passed to the theme_block function to be passed
+ * into a pluggable template engine. Uses block properties to generate a
+ * series of template file suggestions. If none are found, the default
+ * block.html.twig is used.
+ *
+ * Most themes use their own copy of block.html.twig. The default is located
+ * inside "core/modules/block/templates/block.html.twig". Look in there for the
+ * full list of available variables.
+ *
+ * @param array $variables
+ *   An associative array containing:
+ *   - elements: An associative array containing the properties of the element.
+ *     Properties used: #block, #configuration, #children, #plugin_id.
+ */
+function template_preprocess_block(&$variables) {
+  $variables['configuration'] = $variables['elements']['#configuration'];
+  $variables['plugin_id'] = $variables['elements']['#plugin_id'];
+  $variables['base_plugin_id'] = $variables['elements']['#base_plugin_id'];
+  $variables['derivative_plugin_id'] = $variables['elements']['#derivative_plugin_id'];
+  $variables['label'] = !empty($variables['configuration']['label_display']) ? $variables['configuration']['label'] : '';
+  $variables['content'] = $variables['elements']['content'];
+  // A block's label is configuration: it is static. Allow dynamic labels to be
+  // set in the render array.
+  if (isset($variables['elements']['content']['#title']) && !empty($variables['configuration']['label_display'])) {
+    $variables['label'] = $variables['elements']['content']['#title'];
+  }
+
+  // Create a valid HTML ID and make sure it is unique.
+  if (!empty($variables['elements']['#id'])) {
+    $variables['attributes']['id'] = Html::getUniqueId('block-' . $variables['elements']['#id']);
+  }
+
+  // Proactively add aria-describedby if possible to improve accessibility.
+  if ($variables['label'] && isset($variables['attributes']['role'])) {
+    $variables['title_attributes']['id'] = Html::getUniqueId($variables['label']);
+    $variables['attributes']['aria-describedby'] = $variables['title_attributes']['id'];
+  }
+
+}
+
+/**
+ * Implements hook_ENTITY_TYPE_delete() for user_role entities.
+ *
+ * Removes deleted role from blocks that use it.
+ */
+function block_user_role_delete($role) {
+  foreach (Block::loadMultiple() as $block) {
+    /** @var $block \Drupal\block\BlockInterface */
+    $visibility = $block->getVisibility();
+    if (isset($visibility['user_role']['roles'][$role->id()])) {
+      unset($visibility['user_role']['roles'][$role->id()]);
+      $block->getPlugin()->setVisibilityConfig('user_role', $visibility['user_role']);
+      $block->save();
+    }
+  }
+}
+
+/**
+ * Implements hook_ENTITY_TYPE_delete() for menu entities.
+ */
+function block_menu_delete(Menu $menu) {
+  if (!$menu->isSyncing()) {
+    foreach (Block::loadMultiple() as $block) {
+      if ($block->getPluginId() == 'system_menu_block:' . $menu->id()) {
+        $block->delete();
+      }
+    }
+  }
+}
+
+/**
+ * Implements hook_ENTITY_TYPE_delete() for 'configurable_language'.
+ *
+ * Delete the potential block visibility settings of the deleted language.
+ */
+function block_configurable_language_delete(ConfigurableLanguageInterface $language) {
+  // Remove the block visibility settings for the deleted language.
+  foreach (Block::loadMultiple() as $block) {
+    /** @var $block \Drupal\block\BlockInterface */
+    $visibility = $block->getVisibility();
+    if (isset($visibility['language']['langcodes'][$language->id()])) {
+      unset($visibility['language']['langcodes'][$language->id()]);
+      $block->setVisibilityConfig('language', $visibility['language']);
+      $block->save();
+    }
+  }
+}
+
+/**
+ * Implements hook_install().
+ */
+function block_install() {
+  // Because the Block module upon installation unconditionally overrides all
+  // HTML output by selecting a different page display variant, we must
+  // invalidate all cached HTML output.
+  Cache::invalidateTags(['rendered']);
+}

core/modules/block/block.permissions.yml

@@ -0,0 +1,2 @@
+administer blocks:
+  title: 'Administer blocks'

core/modules/block/block.routing.yml

@@ -0,0 +1,59 @@
+block.admin_demo:
+  path: '/admin/structure/block/demo/{theme}'
+  defaults:
+    _controller: '\Drupal\block\Controller\BlockController::demo'
+    _title_callback: 'theme_handler:getName'
+  requirements:
+    _access_theme: 'TRUE'
+    _permission: 'administer blocks'
+  options:
+    _admin_route: FALSE
+
+entity.block.delete_form:
+  path: '/admin/structure/block/manage/{block}/delete'
+  defaults:
+    _entity_form: 'block.delete'
+    _title: 'Delete block'
+  requirements:
+    _permission: 'administer blocks'
+
+entity.block.edit_form:
+  path: '/admin/structure/block/manage/{block}'
+  defaults:
+    _entity_form: 'block.default'
+    _title: 'Configure block'
+  requirements:
+    _entity_access: 'block.update'
+
+block.admin_display:
+  path: '/admin/structure/block'
+  defaults:
+    _controller: '\Drupal\block\Controller\BlockListController::listing'
+    _title: 'Block layout'
+  requirements:
+    _permission: 'administer blocks'
+
+block.admin_display_theme:
+  path: 'admin/structure/block/list/{theme}'
+  defaults:
+    _controller: '\Drupal\block\Controller\BlockListController::listing'
+    _title: 'Block layout'
+  requirements:
+    _access_theme: 'TRUE'
+    _permission: 'administer blocks'
+
+block.admin_add:
+  path: '/admin/structure/block/add/{plugin_id}/{theme}'
+  defaults:
+    _controller: '\Drupal\block\Controller\BlockAddController::blockAddConfigureForm'
+    theme: null
+    _title: 'Configure block'
+  requirements:
+    _permission: 'administer blocks'
+
+block.category_autocomplete:
+  path: '/block-category/autocomplete'
+  defaults:
+    _controller: '\Drupal\block\Controller\CategoryAutocompleteController::autocomplete'
+  requirements:
+    _permission: 'administer blocks'

core/modules/block/block.services.yml

@@ -0,0 +1,27 @@
+services:
+  theme.negotiator.block.admin_demo:
+    class: Drupal\block\Theme\AdminDemoNegotiator
+    tags:
+      - { name: theme_negotiator, priority: 1000 }
+  block.page_display_variant_subscriber:
+    class: Drupal\block\EventSubscriber\BlockPageDisplayVariantSubscriber
+    tags:
+      - { name: event_subscriber }
+  block.current_user_context:
+    class: Drupal\block\EventSubscriber\CurrentUserContext
+    arguments: ['@current_user', '@entity.manager']
+    tags:
+      - { name: 'event_subscriber' }
+  block.current_language_context:
+    class: Drupal\block\EventSubscriber\CurrentLanguageContext
+    arguments: ['@language_manager']
+    tags:
+      - { name: 'event_subscriber' }
+  block.node_route_context:
+    class: Drupal\block\EventSubscriber\NodeRouteContext
+    arguments: ['@current_route_match']
+    tags:
+      - { name: 'event_subscriber' }
+  block.repository:
+    class: Drupal\block\BlockRepository
+    arguments: ['@entity.manager', '@theme.manager', '@context.handler']

core/modules/block/config/schema/block.schema.yml

@@ -0,0 +1,35 @@
+# Schema for the configuration files of the Block module.
+
+block.block.*:
+  type: config_entity
+  label: 'Block'
+  mapping:
+    id:
+      type: string
+      label: 'ID'
+    theme:
+      type: string
+      label: 'Theme'
+    region:
+      type: string
+      label: 'Region'
+    weight:
+      type: integer
+      label: 'Weight'
+    provider:
+      type: string
+      label: 'Provider'
+    plugin:
+      type: string
+      label: 'Plugin'
+    settings:
+      type: block.settings.[%parent.plugin]
+    visibility:
+      type: sequence
+      label: 'Visibility Conditions'
+      sequence:
+        type: condition.plugin.[id]
+        label: 'Visibility Condition'
+
+block.settings.*:
+  type: block_settings

core/modules/block/css/block.admin.css

@@ -0,0 +1,108 @@
+.block-region {
+  background-color: #ff6;
+  margin-top: 4px;
+  margin-bottom: 4px;
+  padding: 3px;
+}
+a.block-demo-backlink,
+a.block-demo-backlink:link,
+a.block-demo-backlink:visited {
+  background-color: #b4d7f0;
+  border-radius: 0 0 10px 10px;
+  color: #000;
+  font-family: "Lucida Grande", Verdana, sans-serif;
+  font-size: small;
+  line-height: 20px;
+  left: 20px; /*LTR*/
+  padding: 5px 10px;
+  position: fixed;
+  z-index: 499;
+}
+a.block-demo-backlink:hover {
+  text-decoration: underline;
+}
+
+.layout-region {
+  box-sizing: border-box;
+}
+.block-list-secondary {
+  border: 1px solid #bfbfbf;
+  border-bottom-width: 0;
+}
+.block-list {
+  padding: 0 0.75em;
+  margin: 0;
+}
+.block-list li {
+  list-style: none;
+  padding: 0.1em 0;
+}
+.block-list a:before {
+  content: '+ ';
+}
+.block-list-secondary .form-type-search {
+  padding: 0 1em;
+}
+.block-form .form-item-settings-admin-label label {
+  display: inline;
+}
+.block-form .form-item-settings-admin-label label:after {
+  content: ':';
+}
+
+/* Wide screens */
+@media
+screen and (min-width: 780px),
+(orientation: landscape) and (min-device-height: 780px) {
+
+  .block-list-primary {
+    float: left; /* LTR */
+    width: 75%;
+    padding-right: 2em;
+  }
+  [dir="rtl"] .block-list-primary {
+    float: right;
+    padding-left: 2em;
+    padding-right: 0;
+  }
+
+  .block-list-secondary {
+    float: right; /* LTR */
+    width: 25%;
+  }
+  [dir="rtl"] .block-list-secondary {
+    float: left;
+  }
+
+  /* @todo File an issue to add a standard class to all text-like inputs */
+  .block-list-secondary .form-autocomplete,
+  .block-list-secondary .form-text,
+  .block-list-secondary .form-tel,
+  .block-list-secondary .form-email,
+  .block-list-secondary .form-url,
+  .block-list-secondary .form-search,
+  .block-list-secondary .form-number,
+  .block-list-secondary .form-color,
+  .block-list-secondary textarea {
+    box-sizing:         border-box;
+    width: 100%;
+    max-width: 100%;
+  }
+}
+
+/**
+ * The vertical toolbar mode gets triggered for narrow screens, which throws off
+ * the intent of media queries written for the viewport width. When the vertical
+ * toolbar is on, we need to suppress layout for the original media width + the
+ * toolbar width (240px). In this case, 240px + 780px.
+ */
+@media
+screen and (max-width: 1020px) {
+
+  .toolbar-vertical.toolbar-tray-open .block-list-primary,
+  .toolbar-vertical.toolbar-tray-open .block-list-secondary {
+    float: none;
+    width: auto;
+    padding-right: 0;
+  }
+}

core/modules/block/js/block.admin.js

@@ -0,0 +1,107 @@
+/**
+ * @file
+ * Block admin behaviors.
+ */
+
+(function ($, Drupal) {
+
+  "use strict";
+
+  /**
+   * Filters the block list by a text input search string.
+   *
+   * Text search input: input.block-filter-text
+   * Target element:    input.block-filter-text[data-element]
+   * Source text:       .block-filter-text-source
+   *
+   * @type {Drupal~behavior}
+   */
+  Drupal.behaviors.blockFilterByText = {
+    attach: function (context, settings) {
+      var $input = $('input.block-filter-text').once('block-filter-text');
+      var $element = $($input.attr('data-element'));
+      var $blocks;
+      var $details;
+
+      /**
+       * Hides the `<details>` element for a category if it has no visible blocks.
+       *
+       * @param {number} index
+       * @param {HTMLElement} element
+       */
+      function hideCategoryDetails(index, element) {
+        var $catDetails = $(element);
+        $catDetails.toggle($catDetails.find('li:visible').length > 0);
+      }
+
+      /**
+       * Filters the block list.
+       *
+       * @param {jQuery.Event} e
+       */
+      function filterBlockList(e) {
+        var query = $(e.target).val().toLowerCase();
+
+        /**
+         * Shows or hides the block entry based on the query.
+         *
+         * @param {number} index
+         * @param {HTMLElement} block
+         */
+        function showBlockEntry(index, block) {
+          var $block = $(block);
+          var $sources = $block.find('.block-filter-text-source');
+          var textMatch = $sources.text().toLowerCase().indexOf(query) !== -1;
+          $block.toggle(textMatch);
+        }
+
+        // Filter if the length of the query is at least 2 characters.
+        if (query.length >= 2) {
+          $blocks.each(showBlockEntry);
+
+          // Note that we first open all <details> to be able to use ':visible'.
+          // Mark the <details> elements that were closed before filtering, so
+          // they can be reclosed when filtering is removed.
+          $details.not('[open]').attr('data-drupal-block-state', 'forced-open');
+          // Hide the category <details> if they don't have any visible rows.
+          $details.attr('open', 'open').each(hideCategoryDetails);
+        }
+        else {
+          $blocks.show();
+          $details.show();
+          // Return <details> elements that had been closed before filtering
+          // to a closed state.
+          $details.filter('[data-drupal-block-state="forced-open"]').removeAttr('open data-drupal-block-state');
+        }
+      }
+
+      if ($element.length) {
+        $details = $element.find('details');
+        $blocks = $details.find('li');
+
+        $input.on('keyup', filterBlockList);
+      }
+    }
+  };
+
+  /**
+   * Highlights the block that was just placed into the block listing.
+   *
+   * @type {Drupal~behavior}
+   */
+  Drupal.behaviors.blockHighlightPlacement = {
+    attach: function (context, settings) {
+      if (settings.blockPlacement) {
+        $(context).find('[data-drupal-selector="edit-blocks"]').once('block-highlight').each(function () {
+          var $container = $(this);
+          // Just scrolling the document.body will not work in Firefox. The html
+          // element is needed as well.
+          $('html, body').animate({
+            scrollTop: $('.js-block-placed').offset().top - $container.offset().top + $container.scrollTop()
+          }, 500);
+        });
+      }
+    }
+  };
+
+}(jQuery, Drupal));

core/modules/block/js/block.js

@@ -0,0 +1,144 @@
+/**
+ * @file
+ * Block behaviors.
+ */
+
+(function ($, window) {
+
+  "use strict";
+
+  /**
+   * Provide the summary information for the block settings vertical tabs.
+   *
+   * @type {Drupal~behavior}
+   */
+  Drupal.behaviors.blockSettingsSummary = {
+    attach: function () {
+      // The drupalSetSummary method required for this behavior is not available
+      // on the Blocks administration page, so we need to make sure this
+      // behavior is processed only if drupalSetSummary is defined.
+      if (typeof jQuery.fn.drupalSetSummary === 'undefined') {
+        return;
+      }
+
+      function checkboxesSummary(context) {
+        var vals = [];
+        var $checkboxes = $(context).find('input[type="checkbox"]:checked + label');
+        var il = $checkboxes.length;
+        for (var i = 0; i < il; i++) {
+          vals.push($($checkboxes[i]).text());
+        }
+        if (!vals.length) {
+          vals.push(Drupal.t('Not restricted'));
+        }
+        return vals.join(', ');
+      }
+
+      $('[data-drupal-selector="edit-visibility-node-type"], [data-drupal-selector="edit-visibility-language"], [data-drupal-selector="edit-visibility-user-role"]').drupalSetSummary(checkboxesSummary);
+
+      $('[data-drupal-selector="edit-visibility-request-path"]').drupalSetSummary(function (context) {
+        var $pages = $(context).find('textarea[name="visibility[request_path][pages]"]');
+        if (!$pages.val()) {
+          return Drupal.t('Not restricted');
+        }
+        else {
+          return Drupal.t('Restricted to certain pages');
+        }
+      });
+    }
+  };
+
+  /**
+   * Move a block in the blocks table from one region to another via select list.
+   *
+   * This behavior is dependent on the tableDrag behavior, since it uses the
+   * objects initialized in that behavior to update the row.
+   *
+   * @type {Drupal~behavior}
+   */
+  Drupal.behaviors.blockDrag = {
+    attach: function (context, settings) {
+      // tableDrag is required and we should be on the blocks admin page.
+      if (typeof Drupal.tableDrag === 'undefined' || typeof Drupal.tableDrag.blocks === 'undefined') {
+        return;
+      }
+
+      var table = $('#blocks');
+      // Get the blocks tableDrag object.
+      var tableDrag = Drupal.tableDrag.blocks;
+      // Add a handler for when a row is swapped, update empty regions.
+      tableDrag.row.prototype.onSwap = function (swappedRow) {
+        checkEmptyRegions(table, this);
+      };
+
+      // Add a handler so when a row is dropped, update fields dropped into new regions.
+      tableDrag.onDrop = function () {
+        var dragObject = this;
+        var $rowElement = $(dragObject.rowObject.element);
+        // Use "region-message" row instead of "region" row because
+        // "region-{region_name}-message" is less prone to regexp match errors.
+        var regionRow = $rowElement.prevAll('tr.region-message').get(0);
+        var regionName = regionRow.className.replace(/([^ ]+[ ]+)*region-([^ ]+)-message([ ]+[^ ]+)*/, '$2');
+        var regionField = $rowElement.find('select.block-region-select');
+        // Check whether the newly picked region is available for this block.
+        if (regionField.find('option[value=' + regionName + ']').length === 0) {
+          // If not, alert the user and keep the block in its old region setting.
+          window.alert(Drupal.t('The block cannot be placed in this region.'));
+          // Simulate that there was a selected element change, so the row is put
+          // back to from where the user tried to drag it.
+          regionField.trigger('change');
+        }
+        else if ($rowElement.prev('tr').is('.region-message')) {
+          var weightField = $rowElement.find('select.block-weight');
+          var oldRegionName = weightField[0].className.replace(/([^ ]+[ ]+)*block-weight-([^ ]+)([ ]+[^ ]+)*/, '$2');
+
+          if (!regionField.is('.block-region-' + regionName)) {
+            regionField.removeClass('block-region-' + oldRegionName).addClass('block-region-' + regionName);
+            weightField.removeClass('block-weight-' + oldRegionName).addClass('block-weight-' + regionName);
+            regionField.val(regionName);
+          }
+        }
+      };
+
+      // Add the behavior to each region select list.
+      $(context).find('select.block-region-select').once('block-region-select').each(function () {
+        $(this).on('change', function (event) {
+          // Make our new row and select field.
+          var row = $(this).closest('tr');
+          var select = $(this);
+          tableDrag.rowObject = new tableDrag.row(row);
+
+          // Find the correct region and insert the row as the last in the region.
+          table.find('.region-' + select[0].value + '-message').nextUntil('.region-message').eq(-1).before(row);
+
+          // Modify empty regions with added or removed fields.
+          checkEmptyRegions(table, row);
+          // Remove focus from selectbox.
+          select.trigger('blur');
+        });
+      });
+
+      var checkEmptyRegions = function (table, rowObject) {
+        table.find('tr.region-message').each(function () {
+          var $this = $(this);
+          // If the dragged row is in this region, but above the message row, swap it down one space.
+          if ($this.prev('tr').get(0) === rowObject.element) {
+            // Prevent a recursion problem when using the keyboard to move rows up.
+            if ((rowObject.method !== 'keyboard' || rowObject.direction === 'down')) {
+              rowObject.swap('after', this);
+            }
+          }
+          // This region has become empty.
+          if ($this.next('tr').is(':not(.draggable)') || $this.next('tr').length === 0) {
+            $this.removeClass('region-populated').addClass('region-empty');
+          }
+          // This region has become populated.
+          else if ($this.is('.region-empty')) {
+            $this.removeClass('region-empty').addClass('region-populated');
+          }
+        });
+      };
+    }
+  };
+
+})(jQuery, window);

core/modules/block/src/BlockAccessControlHandler.php

@@ -0,0 +1,118 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\BlockAccessControlHandler.
+ */
+
+namespace Drupal\block;
+
+use Drupal\Component\Plugin\Exception\ContextException;
+use Drupal\Core\Access\AccessResult;
+use Drupal\Core\Condition\ConditionAccessResolverTrait;
+use Drupal\Core\Entity\EntityAccessControlHandler;
+use Drupal\Core\Entity\EntityHandlerInterface;
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Entity\EntityTypeInterface;
+use Drupal\Core\Executable\ExecutableManagerInterface;
+use Drupal\Core\Plugin\Context\ContextHandlerInterface;
+use Drupal\Core\Plugin\ContextAwarePluginInterface;
+use Drupal\Core\Session\AccountInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * Defines the access control handler for the block entity type.
+ *
+ * @see \Drupal\block\Entity\Block
+ */
+class BlockAccessControlHandler extends EntityAccessControlHandler implements EntityHandlerInterface {
+
+  use ConditionAccessResolverTrait;
+
+  /**
+   * The condition plugin manager.
+   *
+   * @var \Drupal\Core\Executable\ExecutableManagerInterface
+   */
+  protected $manager;
+
+  /**
+   * The plugin context handler.
+   *
+   * @var \Drupal\Core\Plugin\Context\ContextHandlerInterface
+   */
+  protected $contextHandler;
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function createInstance(ContainerInterface $container, EntityTypeInterface $entity_type) {
+    return new static(
+      $entity_type,
+      $container->get('plugin.manager.condition'),
+      $container->get('context.handler')
+    );
+  }
+
+  /**
+   * Constructs the block access control handler instance
+   *
+   * @param \Drupal\Core\Entity\EntityTypeInterface $entity_type
+   *   The entity type definition.
+   * @param \Drupal\Core\Executable\ExecutableManagerInterface $manager
+   *   The ConditionManager for checking visibility of blocks.
+   * @param \Drupal\Core\Plugin\Context\ContextHandlerInterface $context_handler
+   *   The ContextHandler for applying contexts to conditions properly.
+   */
+  public function __construct(EntityTypeInterface $entity_type, ExecutableManagerInterface $manager, ContextHandlerInterface $context_handler) {
+    parent::__construct($entity_type);
+    $this->manager = $manager;
+    $this->contextHandler = $context_handler;
+  }
+
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function checkAccess(EntityInterface $entity, $operation, $langcode, AccountInterface $account) {
+    /** @var \Drupal\block\BlockInterface $entity */
+    if ($operation != 'view') {
+      return parent::checkAccess($entity, $operation, $langcode, $account);
+    }
+
+    // Don't grant access to disabled blocks.
+    if (!$entity->status()) {
+      return AccessResult::forbidden()->cacheUntilEntityChanges($entity);
+    }
+    else {
+      $contexts = $entity->getContexts();
+      $conditions = [];
+      foreach ($entity->getVisibilityConditions() as $condition_id => $condition) {
+        if ($condition instanceof ContextAwarePluginInterface) {
+          try {
+            $this->contextHandler->applyContextMapping($condition, $contexts);
+          }
+          catch (ContextException $e) {
+            return AccessResult::forbidden()->setCacheMaxAge(0);
+          }
+        }
+        $conditions[$condition_id] = $condition;
+      }
+      if ($this->resolveConditions($conditions, 'and') !== FALSE) {
+        // Delegate to the plugin.
+        $access = $entity->getPlugin()->access($account, TRUE);
+      }
+      else {
+        $access = AccessResult::forbidden();
+      }
+      // This should not be hardcoded to an uncacheable access check result, but
+      // in order to fix that, we need condition plugins to return cache contexts,
+      // otherwise it will be impossible to determine by which cache contexts the
+      // result should be varied.
+      // @todo Change this to use $access->cacheUntilEntityChanges($entity) once
+      //   https://www.drupal.org/node/2375695 is resolved.
+      return $access->setCacheMaxAge(0);
+    }
+  }
+
+}

core/modules/block/src/BlockForm.php

@@ -0,0 +1,397 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\BlockForm.
+ */
+
+namespace Drupal\block;
+
+use Drupal\block\Event\BlockContextEvent;
+use Drupal\block\Event\BlockEvents;
+use Drupal\Component\Utility\Html;
+use Drupal\Core\Entity\EntityForm;
+use Drupal\Core\Entity\EntityManagerInterface;
+use Drupal\Core\Executable\ExecutableManagerInterface;
+use Drupal\Core\Extension\ThemeHandlerInterface;
+use Drupal\Core\Form\FormState;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Language\LanguageManagerInterface;
+use Drupal\Core\Plugin\ContextAwarePluginInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+use Symfony\Component\EventDispatcher\EventDispatcherInterface;
+
+/**
+ * Provides form for block instance forms.
+ */
+class BlockForm extends EntityForm {
+
+  /**
+   * The block entity.
+   *
+   * @var \Drupal\block\BlockInterface
+   */
+  protected $entity;
+
+  /**
+   * The block storage.
+   *
+   * @var \Drupal\Core\Entity\EntityStorageInterface
+   */
+  protected $storage;
+
+  /**
+   * The condition plugin manager.
+   *
+   * @var \Drupal\Core\Condition\ConditionManager
+   */
+  protected $manager;
+
+  /**
+   * The event dispatcher service.
+   *
+   * @var \Symfony\Component\EventDispatcher\EventDispatcherInterface
+   */
+  protected $dispatcher;
+
+  /**
+   * The language manager service.
+   *
+   * @var \Drupal\Core\Language\LanguageManagerInterface
+   */
+  protected $language;
+
+  /**
+   * The theme handler.
+   *
+   * @var \Drupal\Core\Extension\ThemeHandler
+   */
+  protected $themeHandler;
+
+  /**
+   * Constructs a BlockForm object.
+   *
+   * @param \Drupal\Core\Entity\EntityManagerInterface $entity_manager
+   *   The entity manager.
+   * @param \Drupal\Core\Executable\ExecutableManagerInterface $manager
+   *   The ConditionManager for building the visibility UI.
+   * @param \Symfony\Component\EventDispatcher\EventDispatcherInterface $dispatcher
+   *   The EventDispatcher for gathering administrative contexts.
+   * @param \Drupal\Core\Language\LanguageManagerInterface $language
+   *   The language manager.
+   * @param \Drupal\Core\Extension\ThemeHandlerInterface $theme_handler
+   * The theme handler.
+   */
+  public function __construct(EntityManagerInterface $entity_manager, ExecutableManagerInterface $manager, EventDispatcherInterface $dispatcher, LanguageManagerInterface $language, ThemeHandlerInterface $theme_handler) {
+    $this->storage = $entity_manager->getStorage('block');
+    $this->manager = $manager;
+    $this->dispatcher = $dispatcher;
+    $this->language = $language;
+    $this->themeHandler = $theme_handler;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container) {
+    return new static(
+      $container->get('entity.manager'),
+      $container->get('plugin.manager.condition'),
+      $container->get('event_dispatcher'),
+      $container->get('language_manager'),
+      $container->get('theme_handler')
+    );
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function form(array $form, FormStateInterface $form_state) {
+    $entity = $this->entity;
+
+    // Store theme settings in $form_state for use below.
+    if (!$theme = $entity->getTheme()) {
+      $theme = $this->config('system.theme')->get('default');
+    }
+    $form_state->set('block_theme', $theme);
+
+    // Store the gathered contexts in the form state for other objects to use
+    // during form building.
+    $form_state->setTemporaryValue('gathered_contexts', $this->dispatcher->dispatch(BlockEvents::ADMINISTRATIVE_CONTEXT, new BlockContextEvent())->getContexts());
+
+    $form['#tree'] = TRUE;
+    $form['settings'] = $entity->getPlugin()->buildConfigurationForm(array(), $form_state);
+    $form['visibility'] = $this->buildVisibilityInterface([], $form_state);
+
+    // If creating a new block, calculate a safe default machine name.
+    $form['id'] = array(
+      '#type' => 'machine_name',
+      '#maxlength' => 64,
+      '#description' => $this->t('A unique name for this block instance. Must be alpha-numeric and underscore separated.'),
+      '#default_value' => !$entity->isNew() ? $entity->id() : $this->getUniqueMachineName($entity),
+      '#machine_name' => array(
+        'exists' => '\Drupal\block\Entity\Block::load',
+        'replace_pattern' => '[^a-z0-9_.]+',
+        'source' => array('settings', 'label'),
+      ),
+      '#required' => TRUE,
+      '#disabled' => !$entity->isNew(),
+    );
+
+    // Theme settings.
+    if ($entity->getTheme()) {
+      $form['theme'] = array(
+        '#type' => 'value',
+        '#value' => $theme,
+      );
+    }
+    else {
+      $theme_options = array();
+      foreach ($this->themeHandler->listInfo() as $theme_name => $theme_info) {
+        if (!empty($theme_info->status)) {
+          $theme_options[$theme_name] = $theme_info->info['name'];
+        }
+      }
+      $form['theme'] = array(
+        '#type' => 'select',
+        '#options' => $theme_options,
+        '#title' => t('Theme'),
+        '#default_value' => $theme,
+        '#ajax' => array(
+          'callback' => '::themeSwitch',
+          'wrapper' => 'edit-block-region-wrapper',
+        ),
+      );
+    }
+
+    // Region settings.
+    $form['region'] = array(
+      '#type' => 'select',
+      '#title' => $this->t('Region'),
+      '#description' => $this->t('Select the region where this block should be displayed.'),
+      '#default_value' => $entity->getRegion(),
+      '#empty_value' => BlockInterface::BLOCK_REGION_NONE,
+      '#options' => system_region_list($theme, REGIONS_VISIBLE),
+      '#prefix' => '<div id="edit-block-region-wrapper">',
+      '#suffix' => '</div>',
+    );
+    $form['#attached']['library'][] = 'block/drupal.block.admin';
+    return $form;
+  }
+
+  /**
+   * Handles switching the available regions based on the selected theme.
+   */
+  public function themeSwitch($form, FormStateInterface $form_state) {
+    $form['region']['#options'] = system_region_list($form_state->getValue('theme'), REGIONS_VISIBLE);
+    return $form['region'];
+  }
+
+  /**
+   * Helper function for building the visibility UI form.
+   *
+   * @param array $form
+   *   An associative array containing the structure of the form.
+   * @param \Drupal\Core\Form\FormStateInterface $form_state
+   *   The current state of the form.
+   *
+   * @return array
+   *   The form array with the visibility UI added in.
+   */
+  protected function buildVisibilityInterface(array $form, FormStateInterface $form_state) {
+    $form['visibility_tabs'] = [
+      '#type' => 'vertical_tabs',
+      '#title' => $this->t('Visibility'),
+      '#parents' => ['visibility_tabs'],
+      '#attached' => [
+        'library' => [
+          'block/drupal.block',
+        ],
+      ],
+    ];
+    // @todo Allow list of conditions to be configured in
+    //   https://www.drupal.org/node/2284687.
+    $visibility = $this->entity->getVisibility();
+    foreach ($this->manager->getDefinitions() as $condition_id => $definition) {
+      // Don't display the current theme condition.
+      if ($condition_id == 'current_theme') {
+        continue;
+      }
+      // Don't display the language condition until we have multiple languages.
+      if ($condition_id == 'language' && !$this->language->isMultilingual()) {
+        continue;
+      }
+      /** @var \Drupal\Core\Condition\ConditionInterface $condition */
+      $condition = $this->manager->createInstance($condition_id, isset($visibility[$condition_id]) ? $visibility[$condition_id] : []);
+      $form_state->set(['conditions', $condition_id], $condition);
+      $condition_form = $condition->buildConfigurationForm([], $form_state);
+      $condition_form['#type'] = 'details';
+      $condition_form['#title'] = $condition->getPluginDefinition()['label'];
+      $condition_form['#group'] = 'visibility_tabs';
+      $form[$condition_id] = $condition_form;
+    }
+
+    if (isset($form['node_type'])) {
+      $form['node_type']['#title'] = $this->t('Content types');
+      $form['node_type']['bundles']['#title'] = $this->t('Content types');
+      $form['node_type']['negate']['#type'] = 'value';
+      $form['node_type']['negate']['#title_display'] = 'invisible';
+      $form['node_type']['negate']['#value'] = $form['node_type']['negate']['#default_value'];
+    }
+    if (isset($form['user_role'])) {
+      $form['user_role']['#title'] = $this->t('Roles');
+      unset($form['user_role']['roles']['#description']);
+      $form['user_role']['negate']['#type'] = 'value';
+      $form['user_role']['negate']['#value'] = $form['user_role']['negate']['#default_value'];
+    }
+    if (isset($form['request_path'])) {
+      $form['request_path']['#title'] = $this->t('Pages');
+      $form['request_path']['negate']['#type'] = 'radios';
+      $form['request_path']['negate']['#default_value'] = (int) $form['request_path']['negate']['#default_value'];
+      $form['request_path']['negate']['#title_display'] = 'invisible';
+      $form['request_path']['negate']['#options'] = [
+        $this->t('Show for the listed pages'),
+        $this->t('Hide for the listed pages'),
+      ];
+    }
+    if (isset($form['language'])) {
+      $form['language']['negate']['#type'] = 'value';
+      $form['language']['negate']['#value'] = $form['language']['negate']['#default_value'];
+    }
+    return $form;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function actions(array $form, FormStateInterface $form_state) {
+    $actions = parent::actions($form, $form_state);
+    $actions['submit']['#value'] = $this->t('Save block');
+    return $actions;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function validate(array $form, FormStateInterface $form_state) {
+    parent::validate($form, $form_state);
+
+    // The Block Entity form puts all block plugin form elements in the
+    // settings form element, so just pass that to the block for validation.
+    $settings = (new FormState())->setValues($form_state->getValue('settings'));
+    // Call the plugin validate handler.
+    $this->entity->getPlugin()->validateConfigurationForm($form, $settings);
+    // Update the original form values.
+    $form_state->setValue('settings', $settings->getValues());
+    $this->validateVisibility($form, $form_state);
+  }
+
+  /**
+   * Helper function to independently validate the visibility UI.
+   *
+   * @param array $form
+   *   A nested array form elements comprising the form.
+   * @param \Drupal\Core\Form\FormStateInterface $form_state
+   *   The current state of the form.
+   */
+  protected function validateVisibility(array $form, FormStateInterface $form_state) {
+    // Validate visibility condition settings.
+    foreach ($form_state->getValue('visibility') as $condition_id => $values) {
+      // All condition plugins use 'negate' as a Boolean in their schema.
+      // However, certain form elements may return it as 0/1. Cast here to
+      // ensure the data is in the expected type.
+      if (array_key_exists('negate', $values)) {
+        $values['negate'] = (bool) $values['negate'];
+      }
+
+      // Allow the condition to validate the form.
+      $condition = $form_state->get(['conditions', $condition_id]);
+      $condition_values = (new FormState())
+        ->setValues($values);
+      $condition->validateConfigurationForm($form, $condition_values);
+      // Update the original form values.
+      $form_state->setValue(['visibility', $condition_id], $condition_values->getValues());
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function submitForm(array &$form, FormStateInterface $form_state) {
+    parent::submitForm($form, $form_state);
+
+    $entity = $this->entity;
+    // The Block Entity form puts all block plugin form elements in the
+    // settings form element, so just pass that to the block for submission.
+    // @todo Find a way to avoid this manipulation.
+    $settings = (new FormState())->setValues($form_state->getValue('settings'));
+
+    // Call the plugin submit handler.
+    $entity->getPlugin()->submitConfigurationForm($form, $settings);
+    // Update the original form values.
+    $form_state->setValue('settings', $settings->getValues());
+
+    // Submit visibility condition settings.
+    foreach ($form_state->getValue('visibility') as $condition_id => $values) {
+      // Allow the condition to submit the form.
+      $condition = $form_state->get(['conditions', $condition_id]);
+      $condition_values = (new FormState())
+        ->setValues($values);
+      $condition->submitConfigurationForm($form, $condition_values);
+      if ($condition instanceof ContextAwarePluginInterface) {
+        $context_mapping = isset($values['context_mapping']) ? $values['context_mapping'] : [];
+        $condition->setContextMapping($context_mapping);
+      }
+      // Update the original form values.
+      $condition_configuration = $condition->getConfiguration();
+      $form_state->setValue(['visibility', $condition_id], $condition_configuration);
+      // Update the visibility conditions on the block.
+      $entity->getVisibilityConditions()->addInstanceId($condition_id, $condition_configuration);
+    }
+
+    // Save the settings of the plugin.
+    $entity->save();
+
+    drupal_set_message($this->t('The block configuration has been saved.'));
+    $form_state->setRedirect(
+      'block.admin_display_theme',
+      array(
+        'theme' => $form_state->getValue('theme'),
+      ),
+      array('query' => array('block-placement' => Html::getClass($this->entity->id())))
+    );
+  }
+
+  /**
+   * Generates a unique machine name for a block.
+   *
+   * @param \Drupal\block\BlockInterface $block
+   *   The block entity.
+   *
+   * @return string
+   *   Returns the unique name.
+   */
+  public function getUniqueMachineName(BlockInterface $block) {
+    $suggestion = $block->getPlugin()->getMachineNameSuggestion();
+
+    // Get all the blocks which starts with the suggested machine name.
+    $query = $this->storage->getQuery();
+    $query->condition('id', $suggestion, 'CONTAINS');
+    $block_ids = $query->execute();
+
+    $block_ids = array_map(function ($block_id) {
+      $parts = explode('.', $block_id);
+      return end($parts);
+    }, $block_ids);
+
+    // Iterate through potential IDs until we get a new one. E.g.
+    // 'plugin', 'plugin_2', 'plugin_3', etc.
+    $count = 1;
+    $machine_default = $suggestion;
+    while (in_array($machine_default, $block_ids)) {
+      $machine_default = $suggestion . '_' . ++$count;
+    }
+    return $machine_default;
+  }
+
+}

core/modules/block/src/BlockInterface.php

@@ -0,0 +1,158 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\BlockInterface.
+ */
+
+namespace Drupal\block;
+
+use Drupal\Core\Config\Entity\ConfigEntityInterface;
+
+/**
+ * Provides an interface defining a block entity.
+ */
+interface BlockInterface extends ConfigEntityInterface {
+
+  /**
+   * Indicates the block label (title) should be displayed to end users.
+   */
+  const BLOCK_LABEL_VISIBLE = 'visible';
+
+  /**
+   * Denotes that a block is not enabled in any region and should not be shown.
+   */
+  const BLOCK_REGION_NONE = -1;
+
+  /**
+   * Returns the plugin instance.
+   *
+   * @return \Drupal\Core\Block\BlockPluginInterface
+   *   The plugin instance for this block.
+   */
+  public function getPlugin();
+
+  /**
+   * Returns the plugin ID.
+   *
+   * @return string
+   *   The plugin ID for this block.
+   */
+  public function getPluginId();
+
+  /**
+   * Returns the region this block is placed in.
+   *
+   * @return string
+   *   The region this block is placed in.
+   */
+  public function getRegion();
+
+  /**
+   * Returns the theme ID.
+   *
+   * @return string
+   *   The theme ID for this block instance.
+   */
+  public function getTheme();
+
+  /**
+   * Returns an array of visibility condition configurations.
+   *
+   * @return array
+   *   An array of visibility condition configuration keyed by the condition ID.
+   */
+  public function getVisibility();
+
+  /**
+   * Gets conditions for this block.
+   *
+   * @return \Drupal\Core\Condition\ConditionInterface[]|\Drupal\Core\Condition\ConditionPluginCollection
+   *   An array or collection of configured condition plugins.
+   */
+  public function getVisibilityConditions();
+
+  /**
+   * Gets a visibility condition plugin instance.
+   *
+   * @param string $instance_id
+   *   The condition plugin instance ID.
+   *
+   * @return \Drupal\Core\Condition\ConditionInterface
+   *   A condition plugin.
+   */
+  public function getVisibilityCondition($instance_id);
+
+  /**
+   * Sets the visibility condition configuration.
+   *
+   * @param string $instance_id
+   *   The condition instance ID.
+   * @param array $configuration
+   *   The condition configuration.
+   *
+   * @return $this
+   */
+  public function setVisibilityConfig($instance_id, array $configuration);
+
+  /**
+   * Get all available contexts.
+   *
+   * @return \Drupal\Component\Plugin\Context\ContextInterface[]
+   *   An array of set contexts, keyed by context name.
+   */
+  public function getContexts();
+
+  /**
+   * Set the contexts that are available for use within the block entity.
+   *
+   * @param \Drupal\Component\Plugin\Context\ContextInterface[] $contexts
+   *   An array of contexts to set on the block.
+   *
+   * @return $this
+   */
+  public function setContexts(array $contexts);
+
+  /**
+   * Returns the weight of this block (used for sorting).
+   *
+   * @return int
+   *   The block weight.
+   */
+  public function getWeight();
+
+  /**
+   * Sets the region this block is placed in.
+   *
+   * @param string $region
+   *   The region to place this block in.
+   *
+   * @return $this
+   */
+  public function setRegion($region);
+
+  /**
+   * Sets the block weight.
+   *
+   * @param int $weight
+   *   The desired weight.
+   *
+   * @return $this
+   */
+  public function setWeight($weight);
+
+  /**
+   * Creates a duplicate of the block entity.
+   *
+   * @param string $new_id
+   *   (optional) The new ID on the duplicate block.
+   * @param string $new_theme
+   *   (optional) The theme on the duplicate block.
+   *
+   * @return static
+   *   A clone of $this with all identifiers unset, so saving it inserts a new
+   *   entity into the storage system.
+   */
+  public function createDuplicateBlock($new_id = NULL, $new_theme = NULL);
+
+}

core/modules/block/src/BlockListBuilder.php

@@ -0,0 +1,420 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\BlockListBuilder.
+ */
+
+namespace Drupal\block;
+
+use Drupal\Component\Utility\Html;
+use Drupal\Core\Block\BlockManagerInterface;
+use Drupal\Component\Serialization\Json;
+use Drupal\Component\Utility\SafeMarkup;
+use Drupal\Core\Config\Entity\ConfigEntityListBuilder;
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Entity\EntityStorageInterface;
+use Drupal\Core\Entity\EntityTypeInterface;
+use Drupal\Core\Form\FormInterface;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Url;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+use Symfony\Component\HttpFoundation\Request;
+
+/**
+ * Defines a class to build a listing of block entities.
+ *
+ * @see \Drupal\block\Entity\Block
+ */
+class BlockListBuilder extends ConfigEntityListBuilder implements FormInterface {
+
+  /**
+   * The regions containing the blocks.
+   *
+   * @var array
+   */
+  protected $regions;
+
+  /**
+   * The theme containing the blocks.
+   *
+   * @var string
+   */
+  protected $theme;
+
+  /**
+   * The current request.
+   *
+   * @var \Symfony\Component\HttpFoundation\Request
+   */
+  protected $request;
+
+  /**
+   * The block manager.
+   *
+   * @var \Drupal\Core\Block\BlockManagerInterface
+   */
+  protected $blockManager;
+
+  /**
+   * Constructs a new BlockListBuilder object.
+   *
+   * @param \Drupal\Core\Entity\EntityTypeInterface $entity_type
+   *   The entity type definition.
+   * @param \Drupal\Core\Entity\EntityStorageInterface $storage
+   *   The entity storage class.
+   * @param \Drupal\Core\Block\BlockManagerInterface $block_manager
+   *   The block manager.
+   */
+  public function __construct(EntityTypeInterface $entity_type, EntityStorageInterface $storage, BlockManagerInterface $block_manager) {
+    parent::__construct($entity_type, $storage);
+
+    $this->blockManager = $block_manager;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function createInstance(ContainerInterface $container, EntityTypeInterface $entity_type) {
+    return new static(
+      $entity_type,
+      $container->get('entity.manager')->getStorage($entity_type->id()),
+      $container->get('plugin.manager.block')
+    );
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function load() {
+    // If no theme was specified, use the current theme.
+    if (!$this->theme) {
+      $this->theme = \Drupal::theme()->getActiveTheme()->getName();
+    }
+
+    // Store the region list.
+    $this->regions = system_region_list($this->theme, REGIONS_VISIBLE);
+
+    // Load only blocks for this theme, and sort them.
+    // @todo Move the functionality of _block_rehash() out of the listing page.
+    $entities = _block_rehash($this->theme);
+
+    // Sort the blocks using \Drupal\block\Entity\Block::sort().
+    uasort($entities, array($this->entityType->getClass(), 'sort'));
+    return $entities;
+  }
+
+  /**
+   * {@inheritdoc}
+   *
+   * @param string|null $theme
+   *   (optional) The theme to display the blocks for. If NULL, the current
+   *   theme will be used.
+   * @param \Symfony\Component\HttpFoundation\Request $request
+   *   The current request.
+   *
+   * @return array
+   *   The block list as a renderable array.
+   */
+  public function render($theme = NULL, Request $request = NULL) {
+    $this->request = $request;
+    // If no theme was specified, use the current theme.
+    $this->theme = $theme ?: \Drupal::theme()->getActiveTheme()->getName();
+
+    return \Drupal::formBuilder()->getForm($this);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getFormId() {
+    return 'block_admin_display_form';
+  }
+
+  /**
+   * Implements \Drupal\Core\Form\FormInterface::buildForm().
+   *
+   * Form constructor for the main block administration form.
+   */
+  public function buildForm(array $form, FormStateInterface $form_state) {
+    $placement = FALSE;
+    if ($this->request->query->has('block-placement')) {
+      $placement = $this->request->query->get('block-placement');
+      $form['#attached']['drupalSettings']['blockPlacement'] = $placement;
+    }
+    $entities = $this->load();
+    $form['#theme'] = array('block_list');
+    $form['#attached']['library'][] = 'core/drupal.tableheader';
+    $form['#attached']['library'][] = 'block/drupal.block';
+    $form['#attached']['library'][] = 'block/drupal.block.admin';
+    $form['#attributes']['class'][] = 'clearfix';
+
+    // Add a last region for disabled blocks.
+    $block_regions_with_disabled = $this->regions + array(BlockInterface::BLOCK_REGION_NONE => BlockInterface::BLOCK_REGION_NONE);
+    $form['block_regions'] = array(
+      '#type' => 'value',
+      '#value' => $block_regions_with_disabled,
+    );
+
+    // Weights range from -delta to +delta, so delta should be at least half
+    // of the amount of blocks present. This makes sure all blocks in the same
+    // region get an unique weight.
+    $weight_delta = round(count($entities) / 2);
+
+    // Build the form tree.
+    $form['edited_theme'] = array(
+      '#type' => 'value',
+      '#value' => $this->theme,
+    );
+    $form['blocks'] = array(
+      '#type' => 'table',
+      '#header' => array(
+        t('Block'),
+        t('Category'),
+        t('Region'),
+        t('Weight'),
+        t('Operations'),
+      ),
+      '#attributes' => array(
+        'id' => 'blocks',
+      ),
+    );
+
+    // Build blocks first for each region.
+    foreach ($entities as $entity_id => $entity) {
+      $definition = $entity->getPlugin()->getPluginDefinition();
+      $blocks[$entity->getRegion()][$entity_id] = array(
+        'label' => $entity->label(),
+        'entity_id' => $entity_id,
+        'weight' => $entity->getWeight(),
+        'entity' => $entity,
+        'category' => $definition['category'],
+      );
+    }
+
+    // Loop over each region and build blocks.
+    foreach ($block_regions_with_disabled as $region => $title) {
+      $form['blocks']['#tabledrag'][] = array(
+        'action' => 'match',
+        'relationship' => 'sibling',
+        'group' => 'block-region-select',
+        'subgroup' => 'block-region-' . $region,
+        'hidden' => FALSE,
+      );
+      $form['blocks']['#tabledrag'][] = array(
+        'action' => 'order',
+        'relationship' => 'sibling',
+        'group' => 'block-weight',
+        'subgroup' => 'block-weight-' . $region,
+      );
+
+      $form['blocks'][$region] = array(
+        '#attributes' => array(
+          'class' => array('region-title', 'region-title-' . $region),
+          'no_striping' => TRUE,
+        ),
+      );
+      $form['blocks'][$region]['title'] = array(
+        '#markup' => $region != BlockInterface::BLOCK_REGION_NONE ? $title : t('Disabled', array(), array('context' => 'Plural')),
+        '#wrapper_attributes' => array(
+          'colspan' => 5,
+        ),
+      );
+
+      $form['blocks'][$region . '-message'] = array(
+        '#attributes' => array(
+          'class' => array(
+            'region-message',
+            'region-' . $region . '-message',
+            empty($blocks[$region]) ? 'region-empty' : 'region-populated',
+          ),
+        ),
+      );
+      $form['blocks'][$region . '-message']['message'] = array(
+        '#markup' => '<em>' . t('No blocks in this region') . '</em>',
+        '#wrapper_attributes' => array(
+          'colspan' => 5,
+        ),
+      );
+
+      if (isset($blocks[$region])) {
+        foreach ($blocks[$region] as $info) {
+          $entity_id = $info['entity_id'];
+
+          $form['blocks'][$entity_id] = array(
+            '#attributes' => array(
+              'class' => array('draggable'),
+            ),
+          );
+          if ($placement && $placement == Html::getClass($entity_id)) {
+            $form['blocks'][$entity_id]['#attributes']['class'][] = 'color-warning';
+            $form['blocks'][$entity_id]['#attributes']['class'][] = 'js-block-placed';
+          }
+          $form['blocks'][$entity_id]['info'] = array(
+            '#markup' => SafeMarkup::checkPlain($info['label']),
+            '#wrapper_attributes' => array(
+              'class' => array('block'),
+            ),
+          );
+          $form['blocks'][$entity_id]['type'] = array(
+            '#markup' => $info['category'],
+          );
+          $form['blocks'][$entity_id]['region-theme']['region'] = array(
+            '#type' => 'select',
+            '#default_value' => $region,
+            '#empty_value' => BlockInterface::BLOCK_REGION_NONE,
+            '#title' => t('Region for @block block', array('@block' => $info['label'])),
+            '#title_display' => 'invisible',
+            '#options' => $this->regions,
+            '#attributes' => array(
+              'class' => array('block-region-select', 'block-region-' . $region),
+            ),
+            '#parents' => array('blocks', $entity_id, 'region'),
+          );
+          $form['blocks'][$entity_id]['region-theme']['theme'] = array(
+            '#type' => 'hidden',
+            '#value' => $this->theme,
+            '#parents' => array('blocks', $entity_id, 'theme'),
+          );
+          $form['blocks'][$entity_id]['weight'] = array(
+            '#type' => 'weight',
+            '#default_value' => $info['weight'],
+            '#delta' => $weight_delta,
+            '#title' => t('Weight for @block block', array('@block' => $info['label'])),
+            '#title_display' => 'invisible',
+            '#attributes' => array(
+              'class' => array('block-weight', 'block-weight-' . $region),
+            ),
+          );
+          $form['blocks'][$entity_id]['operations'] = $this->buildOperations($info['entity']);
+        }
+      }
+    }
+
+    // Do not allow disabling the main system content block when it is present.
+    if (isset($form['blocks']['system_main']['region'])) {
+      $form['blocks']['system_main']['region']['#required'] = TRUE;
+    }
+
+    $form['actions'] = array(
+      '#tree' => FALSE,
+      '#type' => 'actions',
+    );
+    $form['actions']['submit'] = array(
+      '#type' => 'submit',
+      '#value' => t('Save blocks'),
+      '#button_type' => 'primary',
+    );
+
+    $form['place_blocks']['title'] = array(
+      '#type' => 'container',
+      '#markup' => '<h3>' . t('Place blocks') . '</h3>',
+      '#attributes' => array(
+        'class' => array(
+          'entity-meta__header',
+        ),
+      ),
+    );
+
+    $form['place_blocks']['filter'] = array(
+      '#type' => 'search',
+      '#title' => t('Filter'),
+      '#title_display' => 'invisible',
+      '#size' => 30,
+      '#placeholder' => t('Filter by block name'),
+      '#attributes' => array(
+        'class' => array('block-filter-text'),
+        'data-element' => '.entity-meta',
+        'title' => t('Enter a part of the block name to filter by.'),
+      ),
+    );
+
+    $form['place_blocks']['list']['#type'] = 'container';
+    $form['place_blocks']['list']['#attributes']['class'][] = 'entity-meta';
+
+    // Only add blocks which work without any available context.
+    $definitions = $this->blockManager->getDefinitionsForContexts();
+    $sorted_definitions = $this->blockManager->getSortedDefinitions($definitions);
+    foreach ($sorted_definitions as $plugin_id => $plugin_definition) {
+      $category = SafeMarkup::checkPlain($plugin_definition['category']);
+      $category_key = 'category-' . $category;
+      if (!isset($form['place_blocks']['list'][$category_key])) {
+        $form['place_blocks']['list'][$category_key] = array(
+          '#type' => 'details',
+          '#title' => $category,
+          '#open' => TRUE,
+          'content' => array(
+            '#theme' => 'links',
+            '#links' => array(),
+            '#attributes' => array(
+              'class' => array(
+                'block-list',
+              ),
+            ),
+          ),
+        );
+      }
+      $form['place_blocks']['list'][$category_key]['content']['#links'][$plugin_id] = array(
+        'title' => $plugin_definition['admin_label'],
+        'url' => Url::fromRoute('block.admin_add', [
+          'plugin_id' => $plugin_id,
+          'theme' => $this->theme
+        ]),
+        'attributes' => array(
+          'class' => array('use-ajax', 'block-filter-text-source'),
+          'data-dialog-type' => 'modal',
+          'data-dialog-options' => Json::encode(array(
+            'width' => 700,
+          )),
+        ),
+      );
+    }
+    return $form;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getDefaultOperations(EntityInterface $entity) {
+    $operations = parent::getDefaultOperations($entity);
+
+    if (isset($operations['edit'])) {
+      $operations['edit']['title'] = t('Configure');
+    }
+
+    return $operations;
+  }
+
+  /**
+   * Implements \Drupal\Core\Form\FormInterface::validateForm().
+   */
+  public function validateForm(array &$form, FormStateInterface $form_state) {
+    // No validation.
+  }
+
+  /**
+   * Implements \Drupal\Core\Form\FormInterface::submitForm().
+   *
+   * Form submission handler for the main block administration form.
+   */
+  public function submitForm(array &$form, FormStateInterface $form_state) {
+    $entities = $this->storage->loadMultiple(array_keys($form_state->getValue('blocks')));
+    foreach ($entities as $entity_id => $entity) {
+      $entity_values = $form_state->getValue(array('blocks', $entity_id));
+      $entity->setWeight($entity_values['weight']);
+      $entity->setRegion($entity_values['region']);
+      if ($entity->getRegion() == BlockInterface::BLOCK_REGION_NONE) {
+        $entity->disable();
+      }
+      else {
+        $entity->enable();
+      }
+      $entity->save();
+    }
+    drupal_set_message(t('The block settings have been updated.'));
+
+    // Remove any previously set block placement.
+    $this->request->query->remove('block-placement');
+  }
+
+}

core/modules/block/src/BlockPluginCollection.php

@@ -0,0 +1,76 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\BlockPluginCollection.
+ */
+
+namespace Drupal\block;
+
+use Drupal\Component\Plugin\Exception\PluginException;
+use Drupal\Component\Plugin\PluginManagerInterface;
+use Drupal\Component\Utility\SafeMarkup;
+use Drupal\Core\Plugin\DefaultSingleLazyPluginCollection;
+
+/**
+ * Provides a collection of block plugins.
+ */
+class BlockPluginCollection extends DefaultSingleLazyPluginCollection {
+
+  /**
+   * The block ID this plugin collection belongs to.
+   *
+   * @var string
+   */
+  protected $blockId;
+
+  /**
+   * Constructs a new BlockPluginCollection.
+   *
+   * @param \Drupal\Component\Plugin\PluginManagerInterface $manager
+   *   The manager to be used for instantiating plugins.
+   * @param string $instance_id
+   *   The ID of the plugin instance.
+   * @param array $configuration
+   *   An array of configuration.
+   * @param string $block_id
+   *   The unique ID of the block entity using this plugin.
+   */
+  public function __construct(PluginManagerInterface $manager, $instance_id, array $configuration, $block_id) {
+    parent::__construct($manager, $instance_id, $configuration);
+
+    $this->blockId = $block_id;
+  }
+
+  /**
+   * {@inheritdoc}
+   *
+   * @return \Drupal\Core\Block\BlockPluginInterface
+   */
+  public function &get($instance_id) {
+    return parent::get($instance_id);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function initializePlugin($instance_id) {
+    if (!$instance_id) {
+      throw new PluginException(SafeMarkup::format("The block '@block' did not specify a plugin.", array('@block' => $this->blockId)));
+    }
+
+    try {
+      parent::initializePlugin($instance_id);
+    }
+    catch (PluginException $e) {
+      $module = $this->configuration['provider'];
+      // Ignore blocks belonging to uninstalled modules, but re-throw valid
+      // exceptions when the module is installed and the plugin is
+      // misconfigured.
+      if (!$module || \Drupal::moduleHandler()->moduleExists($module)) {
+        throw $e;
+      }
+    }
+  }
+
+}

core/modules/block/src/BlockRepository.php

@@ -0,0 +1,76 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\BlockRepository.
+ */
+
+namespace Drupal\block;
+
+use Drupal\Core\Entity\EntityManagerInterface;
+use Drupal\Core\Plugin\Context\ContextHandlerInterface;
+use Drupal\Core\Theme\ThemeManagerInterface;
+
+/**
+ * Provides a repository for Block config entities.
+ */
+class BlockRepository implements BlockRepositoryInterface {
+
+  /**
+   * The block storage.
+   *
+   * @var \Drupal\Core\Entity\EntityStorageInterface
+   */
+  protected $blockStorage;
+
+  /**
+   * The theme manager.
+   *
+   * @var \Drupal\Core\Theme\ThemeManagerInterface
+   */
+  protected $themeManager;
+
+  /**
+   * Constructs a new BlockRepository.
+   *
+   * @param \Drupal\Core\Entity\EntityManagerInterface $entity_manager
+   *   The entity manager.
+   * @param \Drupal\Core\Theme\ThemeManagerInterface $theme_manager
+   *   The theme manager.
+   * @param \Drupal\Core\Plugin\Context\ContextHandlerInterface $context_handler
+   *   The plugin context handler.
+   */
+  public function __construct(EntityManagerInterface $entity_manager, ThemeManagerInterface $theme_manager, ContextHandlerInterface $context_handler) {
+    $this->blockStorage = $entity_manager->getStorage('block');
+    $this->themeManager = $theme_manager;
+    $this->contextHandler = $context_handler;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getVisibleBlocksPerRegion(array $contexts) {
+    $active_theme = $this->themeManager->getActiveTheme();
+    // Build an array of the region names in the right order.
+    $empty = array_fill_keys($active_theme->getRegions(), array());
+
+    $full = array();
+    foreach ($this->blockStorage->loadByProperties(array('theme' => $active_theme->getName())) as $block_id => $block) {
+      /** @var \Drupal\block\BlockInterface $block */
+      // Set the contexts on the block before checking access.
+      if ($block->setContexts($contexts)->access('view')) {
+        $full[$block->getRegion()][$block_id] = $block;
+      }
+    }
+
+    // Merge it with the actual values to maintain the region ordering.
+    $assignments = array_intersect_key(array_merge($empty, $full), $empty);
+    foreach ($assignments as &$assignment) {
+      // Suppress errors because PHPUnit will indirectly modify the contents,
+      // triggering https://bugs.php.net/bug.php?id=50688.
+      @uasort($assignment, 'Drupal\block\Entity\Block::sort');
+    }
+    return $assignments;
+  }
+
+}

core/modules/block/src/BlockRepositoryInterface.php

@@ -0,0 +1,24 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\BlockRepositoryInterface.
+ */
+
+namespace Drupal\block;
+
+interface BlockRepositoryInterface {
+
+  /**
+   * Returns an array of regions and their block entities.
+   *
+   * @param \Drupal\Component\Plugin\Context\ContextInterface[] $contexts
+   *   An array of contexts to set on the blocks.
+   *
+   * @return array
+   *   The array is first keyed by region machine name, with the values
+   *   containing an array keyed by block ID, with block entities as the values.
+   */
+  public function getVisibleBlocksPerRegion(array $contexts);
+
+}

core/modules/block/src/BlockViewBuilder.php

@@ -0,0 +1,151 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\BlockViewBuilder.
+ */
+
+namespace Drupal\block;
+
+use Drupal\Component\Utility\SafeMarkup;
+use Drupal\Core\Cache\Cache;
+use Drupal\Core\Cache\CacheableMetadata;
+use Drupal\Core\Entity\EntityViewBuilder;
+use Drupal\Core\Entity\EntityViewBuilderInterface;
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Render\Element;
+
+/**
+ * Provides a Block view builder.
+ */
+class BlockViewBuilder extends EntityViewBuilder {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function buildComponents(array &$build, array $entities, array $displays, $view_mode, $langcode = NULL) {
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function view(EntityInterface $entity, $view_mode = 'full', $langcode = NULL) {
+    $build = $this->viewMultiple(array($entity), $view_mode, $langcode);
+    return reset($build);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function viewMultiple(array $entities = array(), $view_mode = 'full', $langcode = NULL) {
+    /** @var \Drupal\block\BlockInterface[] $entities */
+    $build = array();
+    foreach ($entities as  $entity) {
+      $entity_id = $entity->id();
+      $plugin = $entity->getPlugin();
+      $plugin_id = $plugin->getPluginId();
+      $base_id = $plugin->getBaseId();
+      $derivative_id = $plugin->getDerivativeId();
+      $configuration = $plugin->getConfiguration();
+
+      // Create the render array for the block as a whole.
+      // @see template_preprocess_block().
+      $build[$entity_id] = array(
+        '#theme' => 'block',
+        '#attributes' => array(),
+        // All blocks get a "Configure block" contextual link.
+        '#contextual_links' => array(
+          'block' => array(
+            'route_parameters' => array('block' => $entity->id()),
+          ),
+        ),
+        '#weight' => $entity->getWeight(),
+        '#configuration' => $configuration,
+        '#plugin_id' => $plugin_id,
+        '#base_plugin_id' => $base_id,
+        '#derivative_plugin_id' => $derivative_id,
+        '#id' => $entity->id(),
+        '#cache' => [
+          'keys' => ['entity_view', 'block', $entity->id()],
+          'contexts' => $plugin->getCacheContexts(),
+          'tags' => Cache::mergeTags(
+            $this->getCacheTags(), // Block view builder cache tag.
+            $entity->getCacheTags(), // Block entity cache tag.
+            $plugin->getCacheTags() // Block plugin cache tags.
+          ),
+          'max-age' => $plugin->getCacheMaxAge(),
+        ],
+        '#pre_render' => [
+          [$this, 'buildBlock'],
+        ],
+        // Add the entity so that it can be used in the #pre_render method.
+        '#block' => $entity,
+      );
+      $build[$entity_id]['#configuration']['label'] = SafeMarkup::checkPlain($configuration['label']);
+
+      // Don't run in ::buildBlock() to ensure cache keys can be altered. If an
+      // alter hook wants to modify the block contents, it can append another
+      // #pre_render hook.
+      $this->moduleHandler()->alter(array('block_view', "block_view_$base_id"), $build[$entity_id], $plugin);
+    }
+    return $build;
+  }
+
+  /**
+   * #pre_render callback for building a block.
+   *
+   * Renders the content using the provided block plugin, and then:
+   * - if there is no content, aborts rendering, and makes sure the block won't
+   *   be rendered.
+   * - if there is content, moves the contextual links from the block content to
+   *   the block itself.
+   */
+  public function buildBlock($build) {
+    $content = $build['#block']->getPlugin()->build();
+    // Remove the block entity from the render array, to ensure that blocks
+    // can be rendered without the block config entity.
+    unset($build['#block']);
+    if ($content !== NULL && !Element::isEmpty($content)) {
+      // Place the $content returned by the block plugin into a 'content' child
+      // element, as a way to allow the plugin to have complete control of its
+      // properties and rendering (e.g., its own #theme) without conflicting
+      // with the properties used above, or alternate ones used by alternate
+      // block rendering approaches in contrib (e.g., Panels). However, the use
+      // of a child element is an implementation detail of this particular block
+      // rendering approach. Semantically, the content returned by the plugin
+      // "is the" block, and in particular, #attributes and #contextual_links is
+      // information about the *entire* block. Therefore, we must move these
+      // properties from $content and merge them into the top-level element.
+      foreach (array('#attributes', '#contextual_links') as $property) {
+        if (isset($content[$property])) {
+          $build[$property] += $content[$property];
+          unset($content[$property]);
+        }
+      }
+      $build['content'] = $content;
+    }
+    // Either the block's content is completely empty, or it consists only of
+    // cacheability metadata.
+    else {
+      // Abort rendering: render as the empty string and ensure this block is
+      // render cached, so we can avoid the work of having to repeatedly
+      // determine whether the block is empty. E.g. modifying or adding entities
+      // could cause the block to no longer be empty.
+      $build = array(
+        '#markup' => '',
+        '#cache' => $build['#cache'],
+      );
+      // If $content is not empty, then it contains cacheability metadata, and
+      // we must merge it with the existing cacheability metadata. This allows
+      // blocks to be empty, yet still bubble cacheability metadata, to indicate
+      // why they are empty.
+      if (!empty($content)) {
+        CacheableMetadata::createFromRenderArray($build)
+          ->merge(CacheableMetadata::createFromRenderArray($content))
+          ->applyTo($build);
+      }
+    }
+    return $build;
+   }
+
+}

core/modules/block/src/Controller/BlockAddController.php

@@ -0,0 +1,36 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Controller\BlockAddController.
+ */
+
+namespace Drupal\block\Controller;
+
+use Drupal\Core\Controller\ControllerBase;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * Controller for building the block instance add form.
+ */
+class BlockAddController extends ControllerBase {
+
+  /**
+   * Build the block instance add form.
+   *
+   * @param string $plugin_id
+   *   The plugin ID for the block instance.
+   * @param string $theme
+   *   The name of the theme for the block instance.
+   *
+   * @return array
+   *   The block instance edit form.
+   */
+  public function blockAddConfigureForm($plugin_id, $theme) {
+    // Create a block entity.
+    $entity = $this->entityManager()->getStorage('block')->create(array('plugin' => $plugin_id, 'theme' => $theme));
+
+    return $this->entityFormBuilder()->getForm($entity);
+  }
+
+}

core/modules/block/src/Controller/BlockController.php

@@ -0,0 +1,101 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Controller\BlockController.
+ */
+
+namespace Drupal\block\Controller;
+
+use Drupal\Core\Controller\ControllerBase;
+use Drupal\Core\Extension\ThemeHandler;
+use Drupal\Core\Extension\ThemeHandlerInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+use Symfony\Component\HttpFoundation\Request;
+
+/**
+ * Controller routines for admin block routes.
+ */
+class BlockController extends ControllerBase {
+
+  /**
+   * The theme handler.
+   *
+   * @var \Drupal\Core\Extension\ThemeHandlerInterface
+   */
+  protected $themeHandler;
+
+  /**
+   * Constructs a new BlockController instance.
+   *
+   * @param \Drupal\Core\Extension\ThemeHandlerInterface $theme_handler
+   *   The theme handler.
+   */
+  public function __construct(ThemeHandlerInterface $theme_handler) {
+    $this->themeHandler = $theme_handler;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container) {
+    return new static(
+      $container->get('theme_handler')
+    );
+  }
+
+  /**
+   * Returns a block theme demo page.
+   *
+   * @param string $theme
+   *   The name of the theme.
+   *
+   * @return array
+   *   A #type 'page' render array containing the block region demo.
+   */
+  public function demo($theme) {
+    $page = [
+      '#title' => $this->themeHandler->getName($theme),
+      '#type' => 'page',
+      '#attached' => array(
+        'drupalSettings' => [
+          // The block demonstration page is not marked as an administrative
+          // page by \Drupal::service('router.admin_context')->isAdminRoute()
+          // function in order to use the frontend theme. Since JavaScript
+          // relies on a proper separation of admin pages, it needs to know this
+          // is an actual administrative page.
+          'path' => ['currentPathIsAdmin' => TRUE],
+        ],
+        'library' => array(
+          'block/drupal.block.admin',
+        ),
+      ),
+    ];
+
+    // Show descriptions in each visible page region, nothing else.
+    $visible_regions = $this->getVisibleRegionNames($theme);
+    foreach (array_keys($visible_regions) as $region) {
+      $page[$region]['block_description'] = array(
+        '#type' => 'inline_template',
+        '#template' => '<div class="block-region demo-block">{{ region_name }}</div>',
+        '#context' => array('region_name' => $visible_regions[$region]),
+      );
+    }
+
+    return $page;
+  }
+
+  /**
+   * Returns the human-readable list of regions keyed by machine name.
+   *
+   * @param string $theme
+   *   The name of the theme.
+   *
+   * @return array
+   *   An array of human-readable region names keyed by machine name.
+   */
+  protected function getVisibleRegionNames($theme) {
+    return system_region_list($theme, REGIONS_VISIBLE);
+  }
+
+}

core/modules/block/src/Controller/BlockListController.php

@@ -0,0 +1,34 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Controller\BlockListController.
+ */
+
+namespace Drupal\block\Controller;
+
+use Drupal\Core\Entity\Controller\EntityListController;
+use Symfony\Component\HttpFoundation\Request;
+
+/**
+ * Defines a controller to list blocks.
+ */
+class BlockListController extends EntityListController {
+
+  /**
+   * Shows the block administration page.
+   *
+   * @param string|null $theme
+   *   Theme key of block list.
+   * @param \Symfony\Component\HttpFoundation\Request $request
+   *   The current request.
+   *
+   * @return array
+   *   A render array as expected by drupal_render().
+   */
+  public function listing($theme = NULL, Request $request = NULL) {
+    $theme = $theme ?: $this->config('system.theme')->get('default');
+    return $this->entityManager()->getListBuilder('block')->render($theme, $request);
+  }
+
+}

core/modules/block/src/Controller/CategoryAutocompleteController.php

@@ -0,0 +1,68 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Controller\CategoryAutocompleteController.
+ */
+
+namespace Drupal\block\Controller;
+
+use Drupal\Core\Block\BlockManagerInterface;
+use Drupal\Component\Utility\SafeMarkup;
+use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+use Symfony\Component\HttpFoundation\JsonResponse;
+use Symfony\Component\HttpFoundation\Request;
+
+/**
+ * Returns autocomplete responses for block categories.
+ */
+class CategoryAutocompleteController implements ContainerInjectionInterface {
+
+  /**
+   * The block manager.
+   *
+   * @var \Drupal\Core\Block\BlockManagerInterface
+   */
+  protected $blockManager;
+
+  /**
+   * Constructs a new CategoryAutocompleteController.
+   *
+   * @param \Drupal\Core\Block\BlockManagerInterface $block_manager
+   *   The block manager.
+   */
+  public function __construct(BlockManagerInterface $block_manager) {
+    $this->blockManager = $block_manager;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container) {
+    return new static(
+      $container->get('plugin.manager.block')
+    );
+  }
+
+  /**
+   * Retrieves suggestions for block category autocompletion.
+   *
+   * @param \Symfony\Component\HttpFoundation\Request $request
+   *   The current request.
+   *
+   * @return \Symfony\Component\HttpFoundation\JsonResponse
+   *   A JSON response containing autocomplete suggestions.
+   */
+  public function autocomplete(Request $request) {
+    $typed_category = $request->query->get('q');
+    $matches = array();
+    foreach ($this->blockManager->getCategories() as $category) {
+      if (stripos($category, $typed_category) === 0) {
+        $matches[] = array('value' => $category, 'label' => SafeMarkup::checkPlain($category));
+      }
+    }
+    return new JsonResponse($matches);
+  }
+
+}

core/modules/block/src/Entity/Block.php

@@ -0,0 +1,351 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Entity\Block.
+ */
+
+namespace Drupal\block\Entity;
+
+use Drupal\Core\Cache\Cache;
+use Drupal\Core\Condition\ConditionPluginCollection;
+use Drupal\Core\Config\Entity\ConfigEntityBase;
+use Drupal\block\BlockPluginCollection;
+use Drupal\block\BlockInterface;
+use Drupal\Core\Config\Entity\ConfigEntityInterface;
+use Drupal\Core\Entity\EntityWithPluginCollectionInterface;
+use Drupal\Core\Entity\EntityStorageInterface;
+
+/**
+ * Defines a Block configuration entity class.
+ *
+ * @ConfigEntityType(
+ *   id = "block",
+ *   label = @Translation("Block"),
+ *   handlers = {
+ *     "access" = "Drupal\block\BlockAccessControlHandler",
+ *     "view_builder" = "Drupal\block\BlockViewBuilder",
+ *     "list_builder" = "Drupal\block\BlockListBuilder",
+ *     "form" = {
+ *       "default" = "Drupal\block\BlockForm",
+ *       "delete" = "Drupal\block\Form\BlockDeleteForm"
+ *     }
+ *   },
+ *   admin_permission = "administer blocks",
+ *   entity_keys = {
+ *     "id" = "id"
+ *   },
+ *   links = {
+ *     "delete-form" = "/admin/structure/block/manage/{block}/delete",
+ *     "edit-form" = "/admin/structure/block/manage/{block}"
+ *   },
+ *   config_export = {
+ *     "id",
+ *     "theme",
+ *     "region",
+ *     "weight",
+ *     "provider",
+ *     "plugin",
+ *     "settings",
+ *     "visibility",
+ *   },
+ *   lookup_keys = {
+ *     "theme"
+ *   }
+ * )
+ */
+class Block extends ConfigEntityBase implements BlockInterface, EntityWithPluginCollectionInterface {
+
+  /**
+   * The ID of the block.
+   *
+   * @var string
+   */
+  protected $id;
+
+  /**
+   * The plugin instance settings.
+   *
+   * @var array
+   */
+  protected $settings = array();
+
+  /**
+   * The region this block is placed in.
+   *
+   * @var string
+   */
+  protected $region = self::BLOCK_REGION_NONE;
+
+  /**
+   * The block weight.
+   *
+   * @var int
+   */
+  protected $weight;
+
+  /**
+   * The plugin instance ID.
+   *
+   * @var string
+   */
+  protected $plugin;
+
+  /**
+   * The visibility settings for this block.
+   *
+   * @var array
+   */
+  protected $visibility = [];
+
+  /**
+   * The plugin collection that holds the block plugin for this entity.
+   *
+   * @var \Drupal\block\BlockPluginCollection
+   */
+  protected $pluginCollection;
+
+  /**
+   * The available contexts for this block and its visibility conditions.
+   *
+   * @var array
+   */
+  protected $contexts = [];
+
+  /**
+   * The visibility collection.
+   *
+   * @var \Drupal\Core\Condition\ConditionPluginCollection
+   */
+  protected $visibilityCollection;
+
+  /**
+   * The condition plugin manager.
+   *
+   * @var \Drupal\Core\Executable\ExecutableManagerInterface
+   */
+  protected $conditionPluginManager;
+
+  /**
+   * The theme that includes the block plugin for this entity.
+   *
+   * @var string
+   */
+  protected $theme;
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getPlugin() {
+    return $this->getPluginCollection()->get($this->plugin);
+  }
+
+  /**
+   * Encapsulates the creation of the block's LazyPluginCollection.
+   *
+   * @return \Drupal\Component\Plugin\LazyPluginCollection
+   *   The block's plugin collection.
+   */
+  protected function getPluginCollection() {
+    if (!$this->pluginCollection) {
+      $this->pluginCollection = new BlockPluginCollection(\Drupal::service('plugin.manager.block'), $this->plugin, $this->get('settings'), $this->id());
+    }
+    return $this->pluginCollection;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getPluginCollections() {
+    return [
+      'settings' => $this->getPluginCollection(),
+      'visibility' => $this->getVisibilityConditions(),
+    ];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getPluginId() {
+    return $this->plugin;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getRegion() {
+    return $this->region;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getTheme() {
+    return $this->theme;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getWeight() {
+    return $this->weight;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function label() {
+    $settings = $this->get('settings');
+    if ($settings['label']) {
+      return $settings['label'];
+    }
+    else {
+      $definition = $this->getPlugin()->getPluginDefinition();
+      return $definition['admin_label'];
+    }
+  }
+
+  /**
+   * Sorts active blocks by weight; sorts inactive blocks by name.
+   */
+  public static function sort(ConfigEntityInterface $a, ConfigEntityInterface $b) {
+    // Separate enabled from disabled.
+    $status = (int) $b->status() - (int) $a->status();
+    if ($status !== 0) {
+      return $status;
+    }
+    // Sort by weight, unless disabled.
+    if ($a->getRegion() != static::BLOCK_REGION_NONE) {
+      $weight = $a->getWeight() - $b->getWeight();
+      if ($weight) {
+        return $weight;
+      }
+    }
+    // Sort by label.
+    return strcmp($a->label(), $b->label());
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function calculateDependencies() {
+    parent::calculateDependencies();
+    $this->addDependency('theme', $this->theme);
+    return $this->dependencies;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function postSave(EntityStorageInterface $storage, $update = TRUE) {
+    parent::postSave($storage, $update);
+
+    // Entity::postSave() calls Entity::invalidateTagsOnSave(), which only
+    // handles the regular cases. The Block entity has one special case: a
+    // newly created block may *also* appear on any page in the current theme,
+    // so we must invalidate the associated block's cache tag (which includes
+    // the theme cache tag).
+    if (!$update) {
+      Cache::invalidateTags($this->getCacheTags());
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setContexts(array $contexts) {
+    $this->contexts = $contexts;
+    return $this;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getContexts() {
+    return $this->contexts;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getVisibility() {
+    return $this->getVisibilityConditions()->getConfiguration();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setVisibilityConfig($instance_id, array $configuration) {
+    $conditions = $this->getVisibilityConditions();
+    if (!$conditions->has($instance_id)) {
+      $configuration['id'] = $instance_id;
+      $conditions->addInstanceId($instance_id, $configuration);
+    }
+    else {
+      $conditions->setInstanceConfiguration($instance_id, $configuration);
+    }
+    return $this;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getVisibilityConditions() {
+    if (!isset($this->visibilityCollection)) {
+      $this->visibilityCollection = new ConditionPluginCollection($this->conditionPluginManager(), $this->get('visibility'));
+    }
+    return $this->visibilityCollection;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getVisibilityCondition($instance_id) {
+    return $this->getVisibilityConditions()->get($instance_id);
+  }
+
+  /**
+   * Gets the condition plugin manager.
+   *
+   * @return \Drupal\Core\Executable\ExecutableManagerInterface
+   *   The condition plugin manager.
+   */
+  protected function conditionPluginManager() {
+    $this->conditionPluginManager;
+    if (!isset($this->conditionPluginManager)) {
+      $this->conditionPluginManager = \Drupal::service('plugin.manager.condition');
+    }
+    return $this->conditionPluginManager;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setRegion($region) {
+    $this->region = $region;
+    return $this;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setWeight($weight) {
+    $this->weight = $weight;
+    return $this;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function createDuplicateBlock($new_id = NULL, $new_theme = NULL) {
+    $duplicate = parent::createDuplicate();
+    if (!empty($new_id)) {
+      $duplicate->id = $new_id;
+    }
+    if (!empty($new_theme)) {
+      $duplicate->theme = $new_theme;
+    }
+    return $duplicate;
+  }
+
+}

core/modules/block/src/Event/BlockContextEvent.php

@@ -0,0 +1,53 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Event\BlockContextEvent.
+ */
+
+namespace Drupal\block\Event;
+
+use Drupal\Core\Plugin\Context\ContextInterface;
+use Symfony\Component\EventDispatcher\Event;
+
+/**
+ * Event subscribers can add context to be used by the block and its conditions.
+ *
+ * @see \Drupal\block\Event\BlockEvents::ACTIVE_CONTEXT
+ * @see \Drupal\block\Event\BlockEvents::ADMINISTRATIVE_CONTEXT
+ */
+class BlockContextEvent extends Event {
+
+  /**
+   * The array of available contexts for blocks.
+   *
+   * @var array
+   */
+  protected $contexts = [];
+
+  /**
+   * Sets the context object for a given name.
+   *
+   * @param string $name
+   *   The name to store the context object under.
+   * @param \Drupal\Core\Plugin\Context\ContextInterface $context
+   *   The context object to set.
+   *
+   * @return $this
+   */
+  public function setContext($name, ContextInterface $context) {
+    $this->contexts[$name] = $context;
+    return $this;
+  }
+
+  /**
+   * Returns the context objects.
+   *
+   * @return \Drupal\Component\Plugin\Context\ContextInterface[]
+   *   An array of contexts that have been provided.
+   */
+  public function getContexts() {
+    return $this->contexts;
+  }
+
+}

core/modules/block/src/Event/BlockEvents.php

@@ -0,0 +1,55 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Event\BlockEvents.
+ */
+
+namespace Drupal\block\Event;
+
+/**
+ * Defines events for the Block module.
+ */
+final class BlockEvents {
+
+  /**
+   * Name of the event when gathering condition context for a block plugin.
+   *
+   * This event allows you to provide additional context that can be used by
+   * a condition plugin in order to determine the visibility of a block. The
+   * event listener method receives a \Drupal\block\Event\BlockContextEvent
+   * instance. Generally any new context is paired with a new condition plugin
+   * that interprets the provided context and allows the block system to
+   * determine whether or not the block should be displayed.
+   *
+   * @Event
+   *
+   * @see \Drupal\Core\Block\BlockBase::getConditionContexts()
+   * @see \Drupal\block\Event\BlockContextEvent
+   * @see \Drupal\block\EventSubscriber\NodeRouteContext::onBlockActiveContext()
+   * @see \Drupal\Core\Condition\ConditionInterface
+   */
+  const ACTIVE_CONTEXT = 'block.active_context';
+
+  /**
+   * Name of the event when gathering contexts for plugin configuration.
+   *
+   * This event allows you to provide information about your context to the
+   * administration UI without having to provide a value for the context. For
+   * example, during configuration there is no specific node to pass as context.
+   * However, we still need to inform the system that a context named 'node' is
+   * available and provide a definition so that blocks can be configured to use
+   * it.
+   *
+   * The event listener method receives a \Drupal\block\Event\BlockContextEvent
+   * instance.
+   *
+   * @Event
+   *
+   * @see \Drupal\block\BlockForm::form()
+   * @see \Drupal\block\Event\BlockContextEvent
+   * @see \Drupal\block\EventSubscriber\NodeRouteContext::onBlockAdministrativeContext()
+   */
+  const ADMINISTRATIVE_CONTEXT = 'block.administrative_context';
+
+}

core/modules/block/src/EventSubscriber/BlockContextSubscriberBase.php

@@ -0,0 +1,75 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\EventSubscriber\BlockContextSubscriberBase.
+ */
+
+namespace Drupal\block\EventSubscriber;
+
+use Drupal\block\Event\BlockContextEvent;
+use Drupal\block\Event\BlockEvents;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+
+/**
+ * Provides a base class for block context subscribers.
+ */
+abstract class BlockContextSubscriberBase implements EventSubscriberInterface {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function getSubscribedEvents() {
+    $events[BlockEvents::ACTIVE_CONTEXT][] = 'onBlockActiveContext';
+    $events[BlockEvents::ADMINISTRATIVE_CONTEXT][] = 'onBlockAdministrativeContext';
+    return $events;
+  }
+
+  /**
+   * Determines the available run-time contexts.
+   *
+   * For blocks to render correctly, all of the contexts that they require
+   * must be populated with values. So this method must set a value for each
+   * context that it adds. For example:
+   * @code
+   *   // Determine a specific node to pass as context to blocks.
+   *   $node = ...
+   *
+   *   // Set that specific node as the value of the 'node' context.
+   *   $context = new Context(new ContextDefinition('entity:node'));
+   *   $context->setContextValue($node);
+   *   $event->setContext('node.node', $context);
+   * @endcode
+   *
+   * @param \Drupal\block\Event\BlockContextEvent $event
+   *   The Event to which to register available contexts.
+   */
+  abstract public function onBlockActiveContext(BlockContextEvent $event);
+
+  /**
+   * Determines the available configuration-time contexts.
+   *
+   * When a block is being configured, the configuration UI must know which
+   * named contexts are potentially available, but does not care about the
+   * value, since the value can be different for each request, and might not
+   * be available at all during the configuration UI's request.
+   *
+   * For example:
+   * @code
+   *   // During configuration, there is no specific node to pass as context.
+   *   // However, inform the system that a context named 'node.node' is
+   *   // available, and provide its definition, so that blocks can be
+   *   // configured to use it. When the block is rendered, the value of this
+   *   // context will be supplied by onBlockActiveContext().
+   *   $context = new Context(new ContextDefinition('entity:node'));
+   *   $event->setContext('node.node', $context);
+   * @endcode
+   *
+   * @param \Drupal\block\Event\BlockContextEvent $event
+   *   The Event to which to register available contexts.
+   *
+   * @see static::onBlockActiveContext()
+   */
+  abstract public function onBlockAdministrativeContext(BlockContextEvent $event);
+
+}

core/modules/block/src/EventSubscriber/BlockPageDisplayVariantSubscriber.php

@@ -0,0 +1,40 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\EventSubscriber\BlockPageDisplayVariantSubscriber.
+ */
+
+namespace Drupal\block\EventSubscriber;
+
+use Drupal\Core\StringTranslation\StringTranslationTrait;
+use Drupal\Core\Render\PageDisplayVariantSelectionEvent;
+use Drupal\Core\Render\RenderEvents;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+
+/**
+ * Selects the block page display variant.
+ *
+ * @see \Drupal\block\Plugin\DisplayVariant\BlockPageVariant
+ */
+class BlockPageDisplayVariantSubscriber implements EventSubscriberInterface {
+
+  /**
+   * Selects the block page display variant.
+   *
+   * @param \Drupal\Core\Render\PageDisplayVariantSelectionEvent $event
+   *   The event to process.
+   */
+  public function onSelectPageDisplayVariant(PageDisplayVariantSelectionEvent $event) {
+    $event->setPluginId('block_page');
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  static function getSubscribedEvents() {
+    $events[RenderEvents::SELECT_PAGE_DISPLAY_VARIANT][] = array('onSelectPageDisplayVariant');
+    return $events;
+  }
+
+}

core/modules/block/src/EventSubscriber/CurrentLanguageContext.php

@@ -0,0 +1,63 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\EventSubscriber\CurrentLanguageContext.
+ */
+
+namespace Drupal\block\EventSubscriber;
+
+use Drupal\block\Event\BlockContextEvent;
+use Drupal\Core\Language\LanguageManagerInterface;
+use Drupal\Core\Plugin\Context\Context;
+use Drupal\Core\Plugin\Context\ContextDefinition;
+use Drupal\Core\StringTranslation\StringTranslationTrait;
+
+/**
+ * Sets the current language as a context.
+ */
+class CurrentLanguageContext extends BlockContextSubscriberBase {
+
+  use StringTranslationTrait;
+
+  /**
+   * The language manager.
+   *
+   * @var \Drupal\Core\Language\LanguageManagerInterface
+   */
+  protected $languageManager;
+
+  /**
+   * Constructs a new CurrentLanguageContext.
+   *
+   * @param \Drupal\Core\Language\LanguageManagerInterface
+   *   The language manager.
+   */
+  public function __construct(LanguageManagerInterface $language_manager) {
+    $this->languageManager = $language_manager;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function onBlockActiveContext(BlockContextEvent $event) {
+    // Add a context for each language type.
+    $language_types = $this->languageManager->getLanguageTypes();
+    $info = $this->languageManager->getDefinedLanguageTypesInfo();
+    foreach ($language_types as $type_key) {
+      if (isset($info[$type_key]['name'])) {
+        $context = new Context(new ContextDefinition('language', $info[$type_key]['name']));
+        $context->setContextValue($this->languageManager->getCurrentLanguage($type_key));
+        $event->setContext('language.' . $type_key, $context);
+      }
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function onBlockAdministrativeContext(BlockContextEvent $event) {
+    $this->onBlockActiveContext($event);
+  }
+
+}

core/modules/block/src/EventSubscriber/CurrentUserContext.php

@@ -0,0 +1,69 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\EventSubscriber\CurrentUserContext.
+ */
+
+namespace Drupal\block\EventSubscriber;
+
+use Drupal\block\Event\BlockContextEvent;
+use Drupal\Core\Entity\EntityManagerInterface;
+use Drupal\Core\Plugin\Context\Context;
+use Drupal\Core\Plugin\Context\ContextDefinition;
+use Drupal\Core\Session\AccountInterface;
+use Drupal\Core\StringTranslation\StringTranslationTrait;
+
+/**
+ * Sets the current user as a context.
+ */
+class CurrentUserContext extends BlockContextSubscriberBase {
+
+  use StringTranslationTrait;
+
+  /**
+   * The current user.
+   *
+   * @var \Drupal\Core\Session\AccountInterface
+   */
+  protected $account;
+
+  /**
+   * The user storage.
+   *
+   * @var \Drupal\user\UserStorageInterface
+   */
+  protected $userStorage;
+
+  /**
+   * Constructs a new CurrentUserContext.
+   *
+   * @param \Drupal\Core\Session\AccountInterface $account
+   *   The current user.
+   * @param \Drupal\Core\Entity\EntityManagerInterface $entity_manager
+   *   The entity manager.
+   */
+  public function __construct(AccountInterface $account, EntityManagerInterface $entity_manager) {
+    $this->account = $account;
+    $this->userStorage = $entity_manager->getStorage('user');
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function onBlockActiveContext(BlockContextEvent $event) {
+    $current_user = $this->userStorage->load($this->account->id());
+
+    $context = new Context(new ContextDefinition('entity:user', $this->t('Current user')));
+    $context->setContextValue($current_user);
+    $event->setContext('user.current_user', $context);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function onBlockAdministrativeContext(BlockContextEvent $event) {
+    $this->onBlockActiveContext($event);
+  }
+
+}

core/modules/block/src/EventSubscriber/NodeRouteContext.php

@@ -0,0 +1,65 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\EventSubscriber\NodeRouteContext.
+ */
+
+namespace Drupal\block\EventSubscriber;
+
+use Drupal\block\Event\BlockContextEvent;
+use Drupal\Core\Plugin\Context\Context;
+use Drupal\Core\Plugin\Context\ContextDefinition;
+use Drupal\Core\Routing\RouteMatchInterface;
+use Drupal\node\Entity\Node;
+
+/**
+ * Sets the current node as a context on node routes.
+ */
+class NodeRouteContext extends BlockContextSubscriberBase {
+
+  /**
+   * The route match object.
+   *
+   * @var \Drupal\Core\Routing\RouteMatchInterface
+   */
+  protected $routeMatch;
+
+  /**
+   * Constructs a new NodeRouteContext.
+   *
+   * @param \Drupal\Core\Routing\RouteMatchInterface $route_match
+   *   The route match object.
+   */
+  public function __construct(RouteMatchInterface $route_match) {
+    $this->routeMatch = $route_match;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function onBlockActiveContext(BlockContextEvent $event) {
+    if (($route_object = $this->routeMatch->getRouteObject()) && ($route_contexts = $route_object->getOption('parameters')) && isset($route_contexts['node'])) {
+      $context = new Context(new ContextDefinition($route_contexts['node']['type']));
+      if ($node = $this->routeMatch->getParameter('node')) {
+        $context->setContextValue($node);
+      }
+      $event->setContext('node.node', $context);
+    }
+    elseif ($this->routeMatch->getRouteName() == 'node.add') {
+      $node_type = $this->routeMatch->getParameter('node_type');
+      $context = new Context(new ContextDefinition('entity:node'));
+      $context->setContextValue(Node::create(array('type' => $node_type->id())));
+      $event->setContext('node.node', $context);
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function onBlockAdministrativeContext(BlockContextEvent $event) {
+    $context = new Context(new ContextDefinition('entity:node'));
+    $event->setContext('node.node', $context);
+  }
+
+}

core/modules/block/src/Form/BlockDeleteForm.php

@@ -0,0 +1,25 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Form\BlockDeleteForm.
+ */
+
+namespace Drupal\block\Form;
+
+use Drupal\Core\Entity\EntityDeleteForm;
+use Drupal\Core\Url;
+
+/**
+ * Provides a deletion confirmation form for the block instance deletion form.
+ */
+class BlockDeleteForm extends EntityDeleteForm {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getCancelUrl() {
+    return new Url('block.admin_display');
+  }
+
+}

core/modules/block/src/Plugin/Derivative/ThemeLocalTask.php

@@ -0,0 +1,83 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Plugin\Derivative\ThemeLocalTask.
+ */
+
+namespace Drupal\block\Plugin\Derivative;
+
+use Drupal\Component\Plugin\Derivative\DeriverBase;
+use Drupal\Core\Config\ConfigFactoryInterface;
+use Drupal\Core\Extension\ThemeHandlerInterface;
+use Drupal\Core\Plugin\Discovery\ContainerDeriverInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * Provides dynamic tabs based on active themes.
+ */
+class ThemeLocalTask extends DeriverBase implements ContainerDeriverInterface {
+
+  /**
+   * Stores the theme settings config object.
+   *
+   * @var \Drupal\Core\Config\Config
+   */
+  protected $config;
+
+  /**
+   * The theme handler.
+   *
+   * @var \Drupal\Core\Extension\ThemeHandlerInterface
+   */
+  protected $themeHandler;
+
+  /**
+   * Constructs a new ThemeLocalTask.
+   *
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
+   *   The config factory.
+   * @param \Drupal\Core\Extension\ThemeHandlerInterface $theme_handler
+   *   The theme handler.
+   */
+  public function __construct(ConfigFactoryInterface $config_factory, ThemeHandlerInterface $theme_handler) {
+    $this->config = $config_factory->get('system.theme');
+    $this->themeHandler = $theme_handler;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container, $base_plugin_id) {
+    return new static(
+      $container->get('config.factory'),
+      $container->get('theme_handler')
+    );
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getDerivativeDefinitions($base_plugin_definition) {
+    $default_theme = $this->config->get('default');
+
+    foreach ($this->themeHandler->listInfo() as $theme_name => $theme) {
+      if ($theme->status) {
+        $this->derivatives[$theme_name] = $base_plugin_definition;
+        $this->derivatives[$theme_name]['title'] = $theme->info['name'];
+        $this->derivatives[$theme_name]['route_parameters'] = array('theme' => $theme_name);
+      }
+      // Default task!
+      if ($default_theme == $theme_name) {
+        $this->derivatives[$theme_name]['route_name'] = 'block.admin_display';
+        // Emulate default logic because without the base plugin id we can't
+        // change the base_route.
+        $this->derivatives[$theme_name]['weight'] = -10;
+
+        unset($this->derivatives[$theme_name]['route_parameters']);
+      }
+    }
+    return $this->derivatives;
+  }
+
+}

core/modules/block/src/Plugin/DisplayVariant/BlockPageVariant.php

@@ -0,0 +1,188 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Plugin\DisplayVariant\BlockPageVariant.
+ */
+
+namespace Drupal\block\Plugin\DisplayVariant;
+
+use Drupal\block\BlockRepositoryInterface;
+use Drupal\block\Event\BlockContextEvent;
+use Drupal\block\Event\BlockEvents;
+use Drupal\Core\Block\MainContentBlockPluginInterface;
+use Drupal\Core\Block\MessagesBlockPluginInterface;
+use Drupal\Core\Display\PageVariantInterface;
+use Drupal\Core\Entity\EntityTypeInterface;
+use Drupal\Core\Entity\EntityViewBuilderInterface;
+use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
+use Drupal\Core\Display\VariantBase;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+use Symfony\Component\EventDispatcher\EventDispatcherInterface;
+
+/**
+ * Provides a page display variant that decorates the main content with blocks.
+ *
+ * To ensure essential information is displayed, each essential part of a page
+ * has a corresponding block plugin interface, so that BlockPageVariant can
+ * automatically provide a fallback in case no block for each of these
+ * interfaces is placed.
+ *
+ * @see \Drupal\Core\Block\MainContentBlockPluginInterface
+ * @see \Drupal\Core\Block\MessagesBlockPluginInterface
+ *
+ * @PageDisplayVariant(
+ *   id = "block_page",
+ *   admin_label = @Translation("Page with blocks")
+ * )
+ */
+class BlockPageVariant extends VariantBase implements PageVariantInterface, ContainerFactoryPluginInterface {
+
+  /**
+   * The block repository.
+   *
+   * @var \Drupal\block\BlockRepositoryInterface
+   */
+  protected $blockRepository;
+
+  /**
+   * The block view builder.
+   *
+   * @var \Drupal\Core\Entity\EntityViewBuilderInterface
+   */
+  protected $blockViewBuilder;
+
+  /**
+   * The Block entity type list cache tags.
+   *
+   * @var string[]
+   */
+  protected $blockListCacheTags;
+
+  /**
+   * The render array representing the main page content.
+   *
+   * @var array
+   */
+  protected $mainContent = [];
+
+  /**
+   * Constructs a new BlockPageVariant.
+   *
+   * @param array $configuration
+   *   A configuration array containing information about the plugin instance.
+   * @param string $plugin_id
+   *   The plugin ID for the plugin instance.
+   * @param mixed $plugin_definition
+   *   The plugin implementation definition.
+   * @param \Drupal\block\BlockRepositoryInterface $block_repository
+   *   The block repository.
+   * @param \Drupal\Core\Entity\EntityViewBuilderInterface $block_view_builder
+   *   The block view builder.
+   * @param \Symfony\Component\EventDispatcher\EventDispatcherInterface $dispatcher
+   *   The event dispatcher.
+   * @param string[] $block_list_cache_tags
+   *   The Block entity type list cache tags.
+   */
+  public function __construct(array $configuration, $plugin_id, $plugin_definition, BlockRepositoryInterface $block_repository, EntityViewBuilderInterface $block_view_builder, EventDispatcherInterface $dispatcher, array $block_list_cache_tags) {
+    parent::__construct($configuration, $plugin_id, $plugin_definition);
+    $this->blockRepository = $block_repository;
+    $this->blockViewBuilder = $block_view_builder;
+    $this->dispatcher = $dispatcher;
+    $this->blockListCacheTags = $block_list_cache_tags;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
+    return new static(
+      $configuration,
+      $plugin_id,
+      $plugin_definition,
+      $container->get('block.repository'),
+      $container->get('entity.manager')->getViewBuilder('block'),
+      $container->get('event_dispatcher'),
+      $container->get('entity.manager')->getDefinition('block')->getListCacheTags()
+    );
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setMainContent(array $main_content) {
+    $this->mainContent = $main_content;
+    return $this;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function build() {
+    // Track whether blocks showing the main content and messages are displayed.
+    $main_content_block_displayed = FALSE;
+    $messages_block_displayed = FALSE;
+
+    $build = [
+      '#cache' => [
+        'tags' => $this->blockListCacheTags,
+      ],
+    ];
+    $contexts = $this->getActiveBlockContexts();
+    // Load all region content assigned via blocks.
+    foreach ($this->blockRepository->getVisibleBlocksPerRegion($contexts) as $region => $blocks) {
+      /** @var $blocks \Drupal\block\BlockInterface[] */
+      foreach ($blocks as $key => $block) {
+        $block_plugin = $block->getPlugin();
+        if ($block_plugin instanceof MainContentBlockPluginInterface) {
+          $block_plugin->setMainContent($this->mainContent);
+          $main_content_block_displayed = TRUE;
+        }
+        elseif ($block_plugin instanceof MessagesBlockPluginInterface) {
+          $messages_block_displayed = TRUE;
+        }
+        $build[$region][$key] = $this->blockViewBuilder->view($block);
+
+        // The main content block cannot be cached: it is a placeholder for the
+        // render array returned by the controller. It should be rendered as-is,
+        // with other placed blocks "decorating" it.
+        if ($block_plugin instanceof MainContentBlockPluginInterface) {
+          unset($build[$region][$key]['#cache']['keys']);
+        }
+      }
+      if (!empty($build[$region])) {
+        // \Drupal\block\BlockRepositoryInterface::getVisibleBlocksPerRegion()
+        // returns the blocks in sorted order.
+        $build[$region]['#sorted'] = TRUE;
+      }
+    }
+
+    // If no block that shows the main content is displayed, still show the main
+    // content. Otherwise the end user will see all displayed blocks, but not
+    // the main content they came for.
+    if (!$main_content_block_displayed) {
+      $build['content']['system_main'] = $this->mainContent;
+    }
+
+    // If no block displays status messages, still render them.
+    if (!$messages_block_displayed) {
+      $build['content']['messages'] = [
+        '#weight' => -1000,
+        '#type' => 'status_messages',
+      ];
+    }
+
+    return $build;
+  }
+
+  /**
+   * Returns an array of context objects to set on the blocks.
+   *
+   * @return \Drupal\Component\Plugin\Context\ContextInterface[]
+   *   An array of contexts to set on the blocks.
+   */
+  protected function getActiveBlockContexts() {
+    return $this->dispatcher->dispatch(BlockEvents::ACTIVE_CONTEXT, new BlockContextEvent())->getContexts();
+  }
+
+}

core/modules/block/src/Tests/BlockAdminThemeTest.php

@@ -0,0 +1,46 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Tests\BlockAdminThemeTest.
+ */
+
+namespace Drupal\block\Tests;
+
+use Drupal\simpletest\WebTestBase;
+
+/**
+ * Tests the block system with admin themes.
+ *
+ * @group block
+ */
+class BlockAdminThemeTest extends WebTestBase {
+
+  /**
+   * Modules to install.
+   *
+   * @var array
+   */
+  public static $modules = array('block');
+
+  /**
+   * Check for the accessibility of the admin theme on the  block admin page.
+   */
+  function testAdminTheme() {
+    // Create administrative user.
+    $admin_user = $this->drupalCreateUser(array('administer blocks', 'administer themes'));
+    $this->drupalLogin($admin_user);
+
+    // Ensure that access to block admin page is denied when theme is not
+    // installed.
+    $this->drupalGet('admin/structure/block/list/bartik');
+    $this->assertResponse(403);
+
+    // Install admin theme and confirm that tab is accessible.
+    \Drupal::service('theme_handler')->install(array('bartik'));
+    $edit['admin_theme'] = 'bartik';
+    $this->drupalPostForm('admin/appearance', $edit, t('Save configuration'));
+    $this->drupalGet('admin/structure/block/list/bartik');
+    $this->assertResponse(200);
+  }
+}

core/modules/block/src/Tests/BlockCacheTest.php

@@ -0,0 +1,226 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Tests\BlockCacheTest.
+ */
+
+namespace Drupal\block\Tests;
+
+use Drupal\Core\Cache\Cache;
+use Drupal\simpletest\WebTestBase;
+
+/**
+ * Tests block caching.
+ *
+ * @group block
+ */
+class BlockCacheTest extends WebTestBase {
+
+  /**
+   * Modules to install.
+   *
+   * @var array
+   */
+  public static $modules = array('block', 'block_test', 'test_page_test');
+
+  /**
+   * A user with permission to create and edit books and to administer blocks.
+   *
+   * @var object
+   */
+  protected $adminUser;
+
+  /**
+   * An authenticated user to test block caching.
+   *
+   * @var object
+   */
+  protected $normalUser;
+
+  /**
+   * Another authenticated user to test block caching.
+   *
+   * @var object
+   */
+  protected $normalUserAlt;
+
+  /**
+   * The block used by this test.
+   *
+   * @var \Drupal\block\BlockInterface
+   */
+  protected $block;
+
+  protected function setUp() {
+    parent::setUp();
+
+    // Create an admin user, log in and enable test blocks.
+    $this->adminUser = $this->drupalCreateUser(array('administer blocks', 'access administration pages'));
+    $this->drupalLogin($this->adminUser);
+
+    // Create additional users to test caching modes.
+    $this->normalUser = $this->drupalCreateUser();
+    $this->normalUserAlt = $this->drupalCreateUser();
+    // Sync the roles, since drupalCreateUser() creates separate roles for
+    // the same permission sets.
+    $this->normalUserAlt->roles = $this->normalUser->getRoles();
+    $this->normalUserAlt->save();
+
+    // Enable our test block.
+   $this->block = $this->drupalPlaceBlock('test_cache');
+  }
+
+  /**
+   * Test "user.roles" cache context.
+   */
+  function testCachePerRole() {
+    \Drupal::state()->set('block_test.cache_contexts', ['user.roles']);
+
+    // Enable our test block. Set some content for it to display.
+    $current_content = $this->randomMachineName();
+    \Drupal::state()->set('block_test.content', $current_content);
+    $this->drupalLogin($this->normalUser);
+    $this->drupalGet('');
+    $this->assertText($current_content, 'Block content displays.');
+
+    // Change the content, but the cached copy should still be served.
+    $old_content = $current_content;
+    $current_content = $this->randomMachineName();
+    \Drupal::state()->set('block_test.content', $current_content);
+    $this->drupalGet('');
+    $this->assertText($old_content, 'Block is served from the cache.');
+
+    // Clear the cache and verify that the stale data is no longer there.
+    Cache::invalidateTags(array('block_view'));
+    $this->drupalGet('');
+    $this->assertNoText($old_content, 'Block cache clear removes stale cache data.');
+    $this->assertText($current_content, 'Fresh block content is displayed after clearing the cache.');
+
+    // Test whether the cached data is served for the correct users.
+    $old_content = $current_content;
+    $current_content = $this->randomMachineName();
+    \Drupal::state()->set('block_test.content', $current_content);
+    $this->drupalLogout();
+    $this->drupalGet('');
+    $this->assertNoText($old_content, 'Anonymous user does not see content cached per-role for normal user.');
+
+    $this->drupalLogin($this->normalUserAlt);
+    $this->drupalGet('');
+    $this->assertText($old_content, 'User with the same roles sees per-role cached content.');
+
+    $this->drupalLogin($this->adminUser);
+    $this->drupalGet('');
+    $this->assertNoText($old_content, 'Admin user does not see content cached per-role for normal user.');
+
+    $this->drupalLogin($this->normalUser);
+    $this->drupalGet('');
+    $this->assertText($old_content, 'Block is served from the per-role cache.');
+  }
+
+  /**
+   * Test a cacheable block without any cache context.
+   */
+  function testCacheGlobal() {
+    \Drupal::state()->set('block_test.cache_contexts', []);
+
+    $current_content = $this->randomMachineName();
+    \Drupal::state()->set('block_test.content', $current_content);
+
+    $this->drupalGet('');
+    $this->assertText($current_content, 'Block content displays.');
+
+    $old_content = $current_content;
+    $current_content = $this->randomMachineName();
+    \Drupal::state()->set('block_test.content', $current_content);
+
+    $this->drupalLogout();
+    $this->drupalGet('user');
+    $this->assertText($old_content, 'Block content served from cache.');
+  }
+
+  /**
+   * Test non-cacheable block.
+   */
+  function testNoCache() {
+    $this->setBlockCacheConfig(array(
+      'max_age' => 0,
+    ));
+
+    $current_content = $this->randomMachineName();
+    \Drupal::state()->set('block_test.content', $current_content);
+
+    // If max_age = 0 has no effect, the next request would be cached.
+    $this->drupalGet('');
+    $this->assertText($current_content, 'Block content displays.');
+
+    // A cached copy should not be served.
+    $current_content = $this->randomMachineName();
+    \Drupal::state()->set('block_test.content', $current_content);
+    $this->drupalGet('');
+    $this->assertText($current_content, 'Maximum age of zero prevents blocks from being cached.');
+  }
+
+  /**
+   * Test "user" cache context.
+   */
+  function testCachePerUser() {
+    \Drupal::state()->set('block_test.cache_contexts', ['user']);
+
+    $current_content = $this->randomMachineName();
+    \Drupal::state()->set('block_test.content', $current_content);
+    $this->drupalLogin($this->normalUser);
+
+    $this->drupalGet('');
+    $this->assertText($current_content, 'Block content displays.');
+
+    $old_content = $current_content;
+    $current_content = $this->randomMachineName();
+    \Drupal::state()->set('block_test.content', $current_content);
+
+    $this->drupalGet('');
+    $this->assertText($old_content, 'Block is served from per-user cache.');
+
+    $this->drupalLogin($this->normalUserAlt);
+    $this->drupalGet('');
+    $this->assertText($current_content, 'Per-user block cache is not served for other users.');
+
+    $this->drupalLogin($this->normalUser);
+    $this->drupalGet('');
+    $this->assertText($old_content, 'Per-user block cache is persistent.');
+  }
+
+  /**
+   * Test "url" cache context.
+   */
+  function testCachePerPage() {
+    \Drupal::state()->set('block_test.cache_contexts', ['url']);
+
+    $current_content = $this->randomMachineName();
+    \Drupal::state()->set('block_test.content', $current_content);
+
+    $this->drupalGet('test-page');
+    $this->assertText($current_content, 'Block content displays on the test page.');
+
+    $old_content = $current_content;
+    $current_content = $this->randomMachineName();
+    \Drupal::state()->set('block_test.content', $current_content);
+
+    $this->drupalGet('user');
+    $this->assertResponse(200);
+    $this->assertNoText($old_content, 'Block content cached for the test page does not show up for the user page.');
+    $this->drupalGet('test-page');
+    $this->assertResponse(200);
+    $this->assertText($old_content, 'Block content cached for the test page.');
+  }
+
+  /**
+   * Private helper method to set the test block's cache configuration.
+   */
+  private function setBlockCacheConfig($cache_config) {
+    $block = $this->block->getPlugin();
+    $block->setConfigurationValue('cache', $cache_config);
+    $this->block->save();
+  }
+
+}

core/modules/block/src/Tests/BlockConfigSchemaTest.php

@@ -0,0 +1,98 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Tests\BlockConfigSchemaTest.
+ */
+
+namespace Drupal\block\Tests;
+
+use Drupal\block\Entity\Block;
+use Drupal\config\Tests\SchemaCheckTestTrait;
+use Drupal\simpletest\KernelTestBase;
+
+/**
+ * Tests the block config schema.
+ *
+ * @group block
+ */
+class BlockConfigSchemaTest extends KernelTestBase {
+
+  use SchemaCheckTestTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  public static $modules = array(
+    'block',
+    'aggregator',
+    'book',
+    'block_content',
+    'comment',
+    'forum',
+    'node',
+    'statistics',
+    // BlockManager->getModuleName() calls system_get_info().
+    'system',
+    'taxonomy',
+    'user',
+    'text',
+  );
+
+  /**
+   * The typed config manager.
+   *
+   * @var \Drupal\Core\Config\TypedConfigManagerInterface
+   */
+  protected $typedConfig;
+
+  /**
+   * The block manager.
+   *
+   * @var \Drupal\Core\Block\BlockManagerInterface
+   */
+  protected $blockManager;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+
+    $this->typedConfig = \Drupal::service('config.typed');
+    $this->blockManager = \Drupal::service('plugin.manager.block');
+    $this->installEntitySchema('block_content');
+    $this->installEntitySchema('taxonomy_term');
+    $this->installEntitySchema('node');
+    $this->installSchema('book', array('book'));
+  }
+
+  /**
+   * Tests the block config schema for block plugins.
+   */
+  public function testBlockConfigSchema() {
+    foreach ($this->blockManager->getDefinitions() as $block_id => $definition) {
+      $id = strtolower($this->randomMachineName());
+      $block = Block::create(array(
+        'id' => $id,
+        'theme' => 'classy',
+        'weight' => 00,
+        'status' => TRUE,
+        'region' => 'content',
+        'plugin' => $block_id,
+        'settings' => array(
+          'label' => $this->randomMachineName(),
+          'provider' => 'system',
+          'label_display' => FALSE,
+        ),
+        'visibility' => array(),
+      ));
+      $block->save();
+
+      $config = $this->config("block.block.$id");
+      $this->assertEqual($config->get('id'), $id);
+      $this->assertConfigSchema($this->typedConfig, $config->getName(), $config->get());
+    }
+  }
+
+}

core/modules/block/src/Tests/BlockHiddenRegionTest.php

@@ -0,0 +1,75 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Tests\BlockHiddenRegionTest.
+ */
+
+namespace Drupal\block\Tests;
+
+use Drupal\simpletest\WebTestBase;
+
+/**
+ * Tests that a newly installed theme does not inherit blocks to its hidden
+ * regions.
+ *
+ * @group block
+ */
+class BlockHiddenRegionTest extends WebTestBase {
+
+  /**
+   * An administrative user to configure the test environment.
+   */
+  protected $adminUser;
+
+  /**
+   * Modules to install.
+   *
+   * @var array
+   */
+  public static $modules = array('block', 'block_test', 'search');
+
+  protected function setUp() {
+    parent::setUp();
+
+    // Create administrative user.
+    $this->adminUser = $this->drupalCreateUser(array(
+      'administer blocks',
+      'administer themes',
+      'search content',
+      )
+    );
+
+    $this->drupalLogin($this->adminUser);
+    $this->drupalPlaceBlock('search_form_block');
+  }
+
+  /**
+   * Tests that hidden regions do not inherit blocks when a theme is installed.
+   */
+  public function testBlockNotInHiddenRegion() {
+
+    // Ensure that the search form block is displayed.
+    $this->drupalGet('');
+    $this->assertText('Search', 'Block was displayed on the front page.');
+
+    // Install "block_test_theme" and set it as the default theme.
+    $theme = 'block_test_theme';
+    \Drupal::service('theme_handler')->install(array($theme));
+    $this->config('system.theme')
+      ->set('default', $theme)
+      ->save();
+    // Installing a theme will cause the kernel terminate event to rebuild the
+    // router. Simulate that here.
+    \Drupal::service('router.builder')->rebuildIfNeeded();
+
+    // Ensure that "block_test_theme" is set as the default theme.
+    $this->drupalGet('admin/structure/block');
+    $this->assertText('Block test theme(' . t('active tab') . ')', 'Default local task on blocks admin page is the block test theme.');
+
+    // Ensure that the search form block is displayed.
+    $this->drupalGet('');
+    $this->assertText('Search', 'Block was displayed on the front page.');
+  }
+
+}

core/modules/block/src/Tests/BlockHookOperationTest.php

@@ -0,0 +1,58 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Tests\BlockHookOperationTest.
+ *
+ * Tests for Block module regarding hook_entity_operations_alter().
+ */
+
+namespace Drupal\block\Tests;
+
+use Drupal\Component\Utility\Unicode;
+use Drupal\simpletest\WebTestBase;
+
+/**
+ * Implement hook entity operations alter.
+ *
+ * @group block
+ */
+class BlockHookOperationTest extends WebTestBase {
+
+  /**
+   * Modules to install.
+   *
+   * @var array
+   */
+  public static $modules = array('block', 'entity_test');
+
+  protected function setUp() {
+    parent::setUp();
+
+    $permissions = array(
+      'administer blocks',
+    );
+
+    // Create and log in user.
+    $admin_user = $this->drupalCreateUser($permissions);
+    $this->drupalLogin($admin_user);
+  }
+
+  /*
+   * Tests the block list to see if the test_operation link is added.
+   */
+  public function testBlockOperationAlter() {
+    // Add a test block, any block will do.
+    // Set the machine name so the test_operation link can be built later.
+    $block_id = Unicode::strtolower($this->randomMachineName(16));
+    $this->drupalPlaceBlock('system_powered_by_block', array('id' => $block_id));
+
+    // Get the Block listing.
+    $this->drupalGet('admin/structure/block');
+
+    $test_operation_link = 'admin/structure/block/manage/' . $block_id . '/test_operation';
+    // Test if the test_operation link is on the page.
+    $this->assertLinkByHref($test_operation_link);
+  }
+
+}

core/modules/block/src/Tests/BlockHtmlTest.php

@@ -0,0 +1,55 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Tests\BlockHtmlTest.
+ */
+
+namespace Drupal\block\Tests;
+
+use Drupal\simpletest\WebTestBase;
+
+/**
+ * Tests block HTML ID validity.
+ *
+ * @group block
+ */
+class BlockHtmlTest extends WebTestBase {
+
+  /**
+   * Modules to install.
+   *
+   * @var array
+   */
+  public static $modules = array('block', 'block_test');
+
+  protected function setUp() {
+    parent::setUp();
+
+    $this->drupalLogin($this->rootUser);
+
+    // Enable the test_html block, to test HTML ID and attributes.
+    \Drupal::state()->set('block_test.attributes', array('data-custom-attribute' => 'foo'));
+    \Drupal::state()->set('block_test.content', $this->randomMachineName());
+    $this->drupalPlaceBlock('test_html', array('id' => 'test_html_block'));
+
+    // Enable a menu block, to test more complicated HTML.
+    $this->drupalPlaceBlock('system_menu_block:admin');
+  }
+
+  /**
+   * Tests for valid HTML for a block.
+   */
+  function testHtml() {
+    $this->drupalGet('');
+
+    // Ensure that a block's ID is converted to an HTML valid ID, and that
+    // block-specific attributes are added to the same DOM element.
+    $this->assertFieldByXPath('//div[@id="block-test-html-block" and @data-custom-attribute="foo"]', NULL, 'HTML ID and attributes for test block are valid and on the same DOM element.');
+
+    // Ensure expected markup for a menu block.
+    $elements = $this->xpath('//nav[contains(@class, :nav-class)]/ul[contains(@class, :ul-class)]/li', array(':nav-class' => 'block-menu', ':ul-class' => 'menu'));
+    $this->assertTrue(!empty($elements), 'The proper block markup was found.');
+  }
+
+}

core/modules/block/src/Tests/BlockInstallTest.php

@@ -0,0 +1,38 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Tests\BlockInstallTest.
+ */
+
+namespace Drupal\block\Tests;
+
+use Drupal\simpletest\WebTestBase;
+
+/**
+ * Tests block module's installation.
+ *
+ * @group block
+ */
+class BlockInstallTest extends WebTestBase {
+
+  public function testCacheTagInvalidationUponInstallation() {
+    // Warm the page cache.
+    $this->drupalGet('');
+    $this->assertNoText('Powered by Drupal');
+    $this->assertNoCacheTag('config:block_list');
+
+    // Install the block module, and place the "Powered by Drupal" block.
+    $this->container->get('module_installer')->install(['block', 'shortcut']);
+    $this->rebuildContainer();
+    $this->container->get('router.builder')->rebuild();
+    $this->drupalPlaceBlock('system_powered_by_block');
+
+    // Check the same page, block.module's hook_install() should have
+    // invalidated the 'rendered' cache tag to make blocks show up.
+    $this->drupalGet('');
+    $this->assertCacheTag('config:block_list');
+    $this->assertText('Powered by Drupal');
+  }
+
+}

core/modules/block/src/Tests/BlockInterfaceTest.php

@@ -0,0 +1,125 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Tests\BlockInterfaceTest.
+ */
+
+namespace Drupal\block\Tests;
+
+use Drupal\Core\Cache\Cache;
+use Drupal\Component\Utility\SafeMarkup;
+use Drupal\Core\Form\FormState;
+use Drupal\simpletest\KernelTestBase;
+use Drupal\block\BlockInterface;
+
+/**
+ * Tests that the block plugin can work properly without a supporting entity.
+ *
+ * @group block
+ */
+class BlockInterfaceTest extends KernelTestBase {
+  public static $modules = array('system', 'block', 'block_test', 'user');
+
+  /**
+   * Test configuration and subsequent form() and build() method calls.
+   *
+   * This test is attempting to test the existing block plugin api and all
+   * functionality that is expected to remain consistent. The arrays that are
+   * used for comparison can change, but only to include elements that are
+   * contained within BlockBase or the plugin being tested. Likely these
+   * comparison arrays should get smaller, not larger, as more form/build
+   * elements are moved into a more suitably responsible class.
+   *
+   * Instantiation of the plugin is the primary element being tested here. The
+   * subsequent method calls are just attempting to cause a failure if a
+   * dependency outside of the plugin configuration is required.
+   */
+  public function testBlockInterface() {
+    $manager = $this->container->get('plugin.manager.block');
+    $configuration = array(
+      'label' => 'Custom Display Message',
+    );
+    $expected_configuration = array(
+      'id' => 'test_block_instantiation',
+      'label' => 'Custom Display Message',
+      'provider' => 'block_test',
+      'label_display' => BlockInterface::BLOCK_LABEL_VISIBLE,
+      'cache' => array(
+        'max_age' => Cache::PERMANENT,
+      ),
+      'display_message' => 'no message set',
+    );
+    // Initial configuration of the block at construction time.
+    /** @var $display_block \Drupal\Core\Block\BlockPluginInterface */
+    $display_block = $manager->createInstance('test_block_instantiation', $configuration);
+    $this->assertIdentical($display_block->getConfiguration(), $expected_configuration, 'The block was configured correctly.');
+
+    // Updating an element of the configuration.
+    $display_block->setConfigurationValue('display_message', 'My custom display message.');
+    $expected_configuration['display_message'] = 'My custom display message.';
+    $this->assertIdentical($display_block->getConfiguration(), $expected_configuration, 'The block configuration was updated correctly.');
+    $definition = $display_block->getPluginDefinition();
+
+    $period = array(0, 60, 180, 300, 600, 900, 1800, 2700, 3600, 10800, 21600, 32400, 43200, 86400);
+    $period = array_map(array(\Drupal::service('date.formatter'), 'formatInterval'), array_combine($period, $period));
+    $period[0] = '<' . t('no caching') . '>';
+    $period[\Drupal\Core\Cache\Cache::PERMANENT] = t('Forever');
+    $expected_form = array(
+      'provider' => array(
+        '#type' => 'value',
+        '#value' => 'block_test',
+      ),
+      'admin_label' => array(
+        '#type' => 'item',
+        '#title' => t('Block description'),
+        '#markup' => SafeMarkup::checkPlain($definition['admin_label']),
+      ),
+      'label' => array(
+        '#type' => 'textfield',
+        '#title' => 'Title',
+        '#maxlength' => 255,
+        '#default_value' => 'Custom Display Message',
+        '#required' => TRUE,
+      ),
+      'label_display' => array(
+        '#type' => 'checkbox',
+        '#title' => 'Display title',
+        '#default_value' => TRUE,
+        '#return_value' => 'visible',
+      ),
+      'cache' => array(
+        '#type' => 'details',
+        '#title' => t('Cache settings'),
+        'max_age' => array(
+          '#type' => 'select',
+          '#title' => t('Maximum age'),
+          '#description' => t('The maximum time this block may be cached.'),
+          '#default_value' => Cache::PERMANENT,
+          '#options' => $period,
+        ),
+      ),
+      'display_message' => array(
+        '#type' => 'textfield',
+        '#title' => t('Display message'),
+        '#default_value' => 'My custom display message.',
+      ),
+    );
+    $form_state = new FormState();
+    // Ensure there are no form elements that do not belong to the plugin.
+    $actual_form = $display_block->buildConfigurationForm(array(), $form_state);
+    // Remove the visibility sections, as that just tests condition plugins.
+    unset($actual_form['visibility'], $actual_form['visibility_tabs']);
+    $this->assertIdentical($actual_form, $expected_form, 'Only the expected form elements were present.');
+
+    $expected_build = array(
+      '#children' => 'My custom display message.',
+    );
+    // Ensure the build array is proper.
+    $this->assertIdentical($display_block->build(), $expected_build, 'The plugin returned the appropriate build array.');
+
+    // Ensure the machine name suggestion is correct. In truth, this is actually
+    // testing BlockBase's implementation, not the interface itself.
+    $this->assertIdentical($display_block->getMachineNameSuggestion(), 'displaymessage', 'The plugin returned the expected machine name suggestion.');
+  }
+}

core/modules/block/src/Tests/BlockInvalidRegionTest.php

@@ -0,0 +1,67 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Tests\BlockInvalidRegionTest.
+ */
+
+namespace Drupal\block\Tests;
+
+use Drupal\simpletest\WebTestBase;
+use Drupal\block\Entity\Block;
+
+/**
+ * Tests that an active block assigned to a non-existing region triggers the
+ * warning message and is disabled.
+ *
+ * @group block
+ */
+class BlockInvalidRegionTest extends WebTestBase {
+
+  /**
+   * Modules to install.
+   *
+   * @var array
+   */
+  public static $modules = array('block', 'block_test');
+
+  protected function setUp() {
+    parent::setUp();
+    // Create an admin user.
+    $admin_user = $this->drupalCreateUser(array(
+      'administer site configuration',
+      'access administration pages',
+      'administer blocks',
+    ));
+    $this->drupalLogin($admin_user);
+  }
+
+  /**
+   * Tests that blocks assigned to invalid regions work correctly.
+   */
+  function testBlockInInvalidRegion() {
+    // Enable a test block and place it in an invalid region.
+    $block = $this->drupalPlaceBlock('test_html');
+    $block->setRegion('invalid_region');
+    $block->save();
+
+    $warning_message = t('The block %info was assigned to the invalid region %region and has been disabled.', array('%info' => $block->id(), '%region' => 'invalid_region'));
+
+    // Clearing the cache should disable the test block placed in the invalid region.
+    $this->drupalPostForm('admin/config/development/performance', array(), 'Clear all caches');
+    $this->assertRaw($warning_message, 'Enabled block was in the invalid region and has been disabled.');
+
+    // Clear the cache to check if the warning message is not triggered.
+    $this->drupalPostForm('admin/config/development/performance', array(), 'Clear all caches');
+    $this->assertNoRaw($warning_message, 'Disabled block in the invalid region will not trigger the warning.');
+
+    // Place disabled test block in the invalid region of the default theme.
+    $block = Block::load($block->id());
+    $block->setRegion('invalid_region');
+    $block->save();
+
+    // Clear the cache to check if the warning message is not triggered.
+    $this->drupalPostForm('admin/config/development/performance', array(), 'Clear all caches');
+    $this->assertNoRaw($warning_message, 'Disabled block in the invalid region will not trigger the warning.');
+  }
+}

core/modules/block/src/Tests/BlockLanguageCacheTest.php

@@ -0,0 +1,79 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Tests\BlockLanguageCacheTest.
+ */
+
+namespace Drupal\block\Tests;
+
+use Drupal\Component\Utility\Unicode;
+use Drupal\language\Entity\ConfigurableLanguage;
+use Drupal\simpletest\WebTestBase;
+
+/**
+ * Tests display of menu blocks with multiple languages.
+ *
+ * @group block
+ */
+class BlockLanguageCacheTest extends WebTestBase {
+
+  /**
+   * Modules to install.
+   *
+   * @var array
+   */
+  public static $modules = array('block', 'language', 'menu_ui');
+
+  /**
+   * List of langcodes.
+   *
+   * @var array
+   */
+  protected $langcodes = array();
+
+  protected function setUp() {
+    parent::setUp();
+
+    // Create test languages.
+    $this->langcodes = array(ConfigurableLanguage::load('en'));
+    for ($i = 1; $i < 3; ++$i) {
+      $language = ConfigurableLanguage::create(array(
+        'id' => 'l' . $i,
+        'label' => $this->randomString(),
+      ));
+      $language->save();
+      $this->langcodes[$i] = $language;
+    }
+  }
+
+  /**
+   * Creates a block in a language, check blocks page in all languages.
+   */
+  public function testBlockLinks() {
+    // Create admin user to be able to access block admin.
+    $admin_user = $this->drupalCreateUser(array(
+      'administer blocks',
+      'access administration pages',
+      'administer menu',
+    ));
+    $this->drupalLogin($admin_user);
+
+    // Create the block cache for all languages.
+    foreach ($this->langcodes as $langcode) {
+      $this->drupalGet('admin/structure/block', array('language' => $langcode));
+    }
+
+    // Create a menu in the default language.
+    $edit['label'] = $this->randomMachineName();
+    $edit['id'] = Unicode::strtolower($edit['label']);
+    $this->drupalPostForm('admin/structure/menu/add', $edit, t('Save'));
+    $this->assertText(t('Menu @label has been added.', array('@label' => $edit['label'])));
+
+    // Check that the block is listed for all languages.
+    foreach ($this->langcodes as $langcode) {
+      $this->drupalGet('admin/structure/block', array('language' => $langcode));
+      $this->assertText($edit['label']);
+    }
+  }
+}

core/modules/block/src/Tests/BlockLanguageTest.php

@@ -0,0 +1,188 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Tests\BlockLanguageTest.
+ */
+
+namespace Drupal\block\Tests;
+
+use Drupal\simpletest\WebTestBase;
+use Drupal\block\Entity\Block;
+
+/**
+ * Tests if a block can be configured to be only visible on a particular
+ * language.
+ *
+ * @group block
+ */
+class BlockLanguageTest extends WebTestBase {
+
+  /**
+   * An administrative user to configure the test environment.
+   */
+  protected $adminUser;
+
+  /**
+   * Modules to install.
+   *
+   * @var array
+   */
+  public static $modules = array('language', 'block', 'content_translation');
+
+  protected function setUp() {
+    parent::setUp();
+
+    // Create a new user, allow him to manage the blocks and the languages.
+    $this->adminUser = $this->drupalCreateUser(array('administer blocks', 'administer languages'));
+    $this->drupalLogin($this->adminUser);
+
+    // Add predefined language.
+    $edit = array(
+      'predefined_langcode' => 'fr',
+    );
+    $this->drupalPostForm('admin/config/regional/language/add', $edit, t('Add language'));
+    $this->assertText('French', 'Language added successfully.');
+  }
+
+  /**
+   * Tests the visibility settings for the blocks based on language.
+   */
+  public function testLanguageBlockVisibility() {
+    // Check if the visibility setting is available.
+    $default_theme = $this->config('system.theme')->get('default');
+    $this->drupalGet('admin/structure/block/add/system_powered_by_block' . '/' . $default_theme);
+
+    $this->assertField('visibility[language][langcodes][en]', 'Language visibility field is visible.');
+    $this->assertNoField('visibility[language][context_mapping][language]', 'Language type field is not visible.');
+
+    // Enable a standard block and set the visibility setting for one language.
+    $edit = array(
+      'visibility[language][langcodes][en]' => TRUE,
+      'id' => strtolower($this->randomMachineName(8)),
+      'region' => 'sidebar_first',
+    );
+    $this->drupalPostForm('admin/structure/block/add/system_powered_by_block' . '/' . $default_theme, $edit, t('Save block'));
+
+    // Change the default language.
+    $edit = array(
+      'site_default_language' => 'fr',
+    );
+    $this->drupalPostForm('admin/config/regional/language', $edit, t('Save configuration'));
+
+    // Check that a page has a block.
+    $this->drupalGet('en');
+    $this->assertText('Powered by Drupal', 'The body of the custom block appears on the page.');
+
+    // Check that a page doesn't has a block for the current language anymore.
+    $this->drupalGet('fr');
+    $this->assertNoText('Powered by Drupal', 'The body of the custom block does not appear on the page.');
+  }
+
+  /**
+   * Tests if the visibility settings are removed if the language is deleted.
+   */
+  public function testLanguageBlockVisibilityLanguageDelete() {
+    // Enable a standard block and set the visibility setting for one language.
+    $edit = array(
+      'visibility' => array(
+        'language' => array(
+          'langcodes' => array(
+            'fr' => 'fr',
+          ),
+        ),
+      ),
+    );
+    $block = $this->drupalPlaceBlock('system_powered_by_block', $edit);
+
+    // Check that we have the language in config after saving the setting.
+    $visibility = $block->getVisibility();
+    $this->assertEqual('fr', $visibility['language']['langcodes']['fr'], 'Language is set in the block configuration.');
+
+    // Delete the language.
+    $this->drupalPostForm('admin/config/regional/language/delete/fr', array(), t('Delete'));
+
+    // Check that the language is no longer stored in the configuration after
+    // it is deleted.
+    $block = Block::load($block->id());
+    $visibility = $block->getVisibility();
+    $this->assertTrue(empty($visibility['language']['langcodes']['fr']), 'Language is no longer not set in the block configuration after deleting the block.');
+
+    // Ensure that the block visibility for language is gone from the UI.
+    $this->drupalGet('admin/structure/block');
+    $this->clickLink('Configure');
+    $elements = $this->xpath('//details[@id="edit-visibility-language"]');
+    $this->assertTrue(empty($elements));
+  }
+
+  /**
+   * Tests block language visibility with different language types.
+   */
+  public function testMultipleLanguageTypes() {
+    // Customize content language detection to be different from interface
+    // language detection.
+    $edit = [
+      // Interface language detection: only using session.
+      'language_interface[enabled][language-url]' => FALSE,
+      'language_interface[enabled][language-session]' => TRUE,
+      // Content language detection: only using URL.
+      'language_content[configurable]' => TRUE,
+      'language_content[enabled][language-url]' => TRUE,
+      'language_content[enabled][language-interface]' => FALSE,
+    ];
+    $this->drupalPostForm('admin/config/regional/language/detection', $edit, t('Save settings'));
+
+    // Check if the visibility setting is available with a type setting.
+    $default_theme = $this->config('system.theme')->get('default');
+    $this->drupalGet('admin/structure/block/add/system_powered_by_block' . '/' . $default_theme);
+    $this->assertField('visibility[language][langcodes][en]', 'Language visibility field is visible.');
+    $this->assertField('visibility[language][context_mapping][language]', 'Language type field is visible.');
+
+    // Enable a standard block and set visibility to French only.
+    $block_id = strtolower($this->randomMachineName(8));
+    $edit = [
+      'visibility[language][context_mapping][language]' => 'language.language_interface',
+      'visibility[language][langcodes][fr]' => TRUE,
+      'id' => $block_id,
+      'region' => 'sidebar_first',
+    ];
+    $this->drupalPostForm('admin/structure/block/add/system_powered_by_block' . '/' . $default_theme, $edit, t('Save block'));
+
+    // Interface negotiation depends on request arguments.
+    $this->drupalGet('node', ['query' => ['language' => 'en']]);
+    $this->assertNoText('Powered by Drupal', 'The body of the block does not appear on the page.');
+    $this->drupalGet('node', ['query' => ['language' => 'fr']]);
+    $this->assertText('Powered by Drupal', 'The body of the block appears on the page.');
+
+    // Re-login in order to clear the interface language stored in the session.
+    $this->drupalLogout();
+    $this->drupalLogin($this->adminUser);
+
+    // Content language does not depend on session/request arguments.
+    // It will fall back on English (site default) and not display the block.
+    $this->drupalGet('en');
+    $this->assertNoText('Powered by Drupal', 'The body of the block does not appear on the page.');
+    $this->drupalGet('fr');
+    $this->assertNoText('Powered by Drupal', 'The body of the block does not appear on the page.');
+
+    // Change visibility to now depend on content language for this block.
+    $edit = [
+      'visibility[language][context_mapping][language]' => 'language.language_content'
+    ];
+    $this->drupalPostForm('admin/structure/block/manage/' . $block_id, $edit, t('Save block'));
+
+    // Content language negotiation does not depend on request arguments.
+    // It will fall back on English (site default) and not display the block.
+    $this->drupalGet('node', ['query' => ['language' => 'en']]);
+    $this->assertNoText('Powered by Drupal', 'The body of the block does not appear on the page.');
+    $this->drupalGet('node', ['query' => ['language' => 'fr']]);
+    $this->assertNoText('Powered by Drupal', 'The body of the block does not appear on the page.');
+
+    // Content language negotiation depends on path prefix.
+    $this->drupalGet('en');
+    $this->assertNoText('Powered by Drupal', 'The body of the block does not appear on the page.');
+    $this->drupalGet('fr');
+    $this->assertText('Powered by Drupal', 'The body of the block appears on the page.');
+  }
+
+}

core/modules/block/src/Tests/BlockRenderOrderTest.php

@@ -0,0 +1,84 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Tests\BlockRenderOrderTest.
+ */
+
+namespace Drupal\block\Tests;
+
+use Drupal\Component\Utility\Html;
+use Drupal\simpletest\WebTestBase;
+
+/**
+ * Tests blocks are being rendered in order by weight.
+ *
+ * @group block
+ */
+class BlockRenderOrderTest extends WebTestBase {
+
+  /**
+   * Modules to install.
+   *
+   * @var array
+   */
+  public static $modules = array('node', 'block');
+
+  protected function setUp() {
+    parent::setUp();
+    // Create a test user.
+    $end_user = $this->drupalCreateUser(array(
+      'access content',
+    ));
+    $this->drupalLogin($end_user);
+  }
+
+  /**
+   * Tests the render order of the blocks.
+   */
+  function testBlockRenderOrder() {
+    // Enable test blocks and place them in the same region.
+    $region = 'header';
+    $test_blocks = array(
+      'stark_powered' => array(
+        'weight' => '-3',
+        'id' => 'stark_powered',
+        'label' => 'Test block A',
+      ),
+      'stark_by' => array(
+        'weight' => '3',
+        'id' => 'stark_by',
+        'label' => 'Test block C',
+      ),
+      'stark_drupal' => array(
+        'weight' => '3',
+        'id' => 'stark_drupal',
+        'label' => 'Test block B',
+      ),
+    );
+
+    // Place the test blocks.
+    foreach ($test_blocks as $test_block) {
+      $this->drupalPlaceBlock('system_powered_by_block', array(
+        'label' => $test_block['label'],
+        'region' => $region,
+        'weight' => $test_block['weight'],
+        'id' => $test_block['id'],
+      ));
+    }
+
+    $this->drupalGet('');
+    $test_content = $this->getRawContent('');
+
+    $controller = $this->container->get('entity.manager')->getStorage('block');
+    foreach ($controller->loadMultiple() as $return_block) {
+      $id = $return_block->id();
+      if ($return_block_weight = $return_block->getWeight()) {
+        $this->assertTrue($test_blocks[$id]['weight'] == $return_block_weight, 'Block weight is set as "' . $return_block_weight  . '" for ' . $id . ' block.');
+        $position[$id] = strpos($test_content, Html::getClass('block-' . $test_blocks[$id]['id']));
+      }
+    }
+    $this->assertTrue($position['stark_powered'] < $position['stark_by'], 'Blocks with different weight are rendered in the correct order.');
+    $this->assertTrue($position['stark_drupal'] < $position['stark_by'], 'Blocks with identical weight are rendered in alphabetical order.');
+  }
+}

core/modules/block/src/Tests/BlockStorageUnitTest.php

@@ -0,0 +1,164 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Tests\BlockStorageUnitTest.
+ */
+
+namespace Drupal\block\Tests;
+
+use Drupal\Core\Cache\Cache;
+use Drupal\Core\Config\Entity\ConfigEntityStorage;
+use Drupal\simpletest\KernelTestBase;
+use Drupal\block_test\Plugin\Block\TestHtmlBlock;
+use Drupal\Component\Plugin\Exception\PluginException;
+use Drupal\block\Entity\Block;
+use Drupal\block\BlockInterface;
+
+/**
+ * Tests the storage of blocks.
+ *
+ * @group block
+ */
+class BlockStorageUnitTest extends KernelTestBase {
+
+  /**
+   * Modules to install.
+   *
+   * @var array
+   */
+  public static $modules = array('block', 'block_test');
+
+  /**
+   * The block storage.
+   *
+   * @var \Drupal\Core\Config\Entity\ConfigEntityStorageInterface.
+   */
+  protected $controller;
+
+  protected function setUp() {
+    parent::setUp();
+
+    $this->controller = $this->container->get('entity.manager')->getStorage('block');
+  }
+
+  /**
+   * Tests CRUD operations.
+   */
+  public function testBlockCRUD() {
+    $this->assertTrue($this->controller instanceof ConfigEntityStorage, 'The block storage is loaded.');
+
+    // Run each test method in the same installation.
+    $this->createTests();
+    $this->loadTests();
+    $this->deleteTests();
+  }
+
+  /**
+   * Tests the creation of blocks.
+   */
+  protected function createTests() {
+    // Attempt to create a block without a plugin.
+    try {
+      $entity = $this->controller->create(array());
+      $entity->getPlugin();
+      $this->fail('A block without a plugin was created with no exception thrown.');
+    }
+    catch (PluginException $e) {
+      $this->assertEqual('The block \'\' did not specify a plugin.', $e->getMessage(), 'An exception was thrown when a block was created without a plugin.');
+    }
+
+    // Create a block with only required values.
+    $entity = $this->controller->create(array(
+      'id' => 'test_block',
+      'theme' => 'stark',
+      'plugin' => 'test_html',
+    ));
+    $entity->save();
+
+    $this->assertTrue($entity instanceof Block, 'The newly created entity is a Block.');
+
+    // Verify all of the block properties.
+    $actual_properties = $this->config('block.block.test_block')->get();
+    $this->assertTrue(!empty($actual_properties['uuid']), 'The block UUID is set.');
+    unset($actual_properties['uuid']);
+
+    // Ensure that default values are filled in.
+    $expected_properties = array(
+      'langcode' => \Drupal::languageManager()->getDefaultLanguage()->getId(),
+      'status' => TRUE,
+      'dependencies' => array('module' => array('block_test'), 'theme' => array('stark')),
+      'id' => 'test_block',
+      'theme' => 'stark',
+      'region' => '-1',
+      'weight' => NULL,
+      'provider' => NULL,
+      'plugin' => 'test_html',
+      'settings' => array(
+        'id' => 'test_html',
+        'label' => '',
+        'provider' => 'block_test',
+        'label_display' => BlockInterface::BLOCK_LABEL_VISIBLE,
+        'cache' => array(
+          'max_age' => Cache::PERMANENT,
+        ),
+      ),
+      'visibility' => array(),
+    );
+
+    $this->assertIdentical($actual_properties, $expected_properties);
+
+    $this->assertTrue($entity->getPlugin() instanceof TestHtmlBlock, 'The entity has an instance of the correct block plugin.');
+  }
+
+  /**
+   * Tests the loading of blocks.
+   */
+  protected function loadTests() {
+    $entity = $this->controller->load('test_block');
+
+    $this->assertTrue($entity instanceof Block, 'The loaded entity is a Block.');
+
+    // Verify several properties of the block.
+    $this->assertEqual($entity->getRegion(), '-1');
+    $this->assertTrue($entity->status());
+    $this->assertEqual($entity->getTheme(), 'stark');
+    $this->assertTrue($entity->uuid());
+  }
+
+  /**
+   * Tests the deleting of blocks.
+   */
+  protected function deleteTests() {
+    $entity = $this->controller->load('test_block');
+
+    // Ensure that the storage isn't currently empty.
+    $config_storage = $this->container->get('config.storage');
+    $config = $config_storage->listAll('block.block.');
+    $this->assertFalse(empty($config), 'There are blocks in config storage.');
+
+    // Delete the block.
+    $entity->delete();
+
+    // Ensure that the storage is now empty.
+    $config = $config_storage->listAll('block.block.');
+    $this->assertTrue(empty($config), 'There are no blocks in config storage.');
+  }
+
+  /**
+   * Tests the installation of default blocks.
+   */
+  public function testDefaultBlocks() {
+    \Drupal::service('theme_handler')->install(['classy']);
+    $entities = $this->controller->loadMultiple();
+    $this->assertTrue(empty($entities), 'There are no blocks initially.');
+
+    // Install the block_test.module, so that its default config is installed.
+    $this->installConfig(array('block_test'));
+
+    $entities = $this->controller->loadMultiple();
+    $entity = reset($entities);
+    $this->assertEqual($entity->id(), 'test_block', 'The default test block was loaded.');
+  }
+
+}

core/modules/block/src/Tests/BlockSystemBrandingTest.php

@@ -0,0 +1,116 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Tests\BlockSystemBrandingTest.
+ */
+
+namespace Drupal\block\Tests;
+
+/**
+ * Tests branding block display.
+ *
+ * @group block
+ */
+class BlockSystemBrandingTest extends BlockTestBase {
+
+  /**
+   * Modules to install.
+   *
+   * @var array
+   */
+  public static $modules = array('block', 'system');
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+    // Set a site slogan.
+    $this->config('system.site')
+      ->set('slogan', 'Community plumbing')
+      ->save();
+    // Add the system branding block to the page.
+    $this->drupalPlaceBlock('system_branding_block', array('region' => 'header', 'id' => 'site-branding'));
+  }
+
+  /**
+   * Tests system branding block configuration.
+   */
+  public function testSystemBrandingSettings() {
+    $site_logo_xpath = '//div[@id="block-site-branding"]//a[@class="site-logo"]';
+    $site_name_xpath = '//div[@id="block-site-branding"]//div[@class="site-name"]';
+    $site_slogan_xpath = '//div[@id="block-site-branding"]//div[@class="site-slogan"]';
+
+    // Set default block settings.
+    $this->drupalGet('');
+    $site_logo_element = $this->xpath($site_logo_xpath);
+    $site_name_element = $this->xpath($site_name_xpath);
+    $site_slogan_element = $this->xpath($site_slogan_xpath);
+    // Test that all branding elements are displayed.
+    $this->assertTrue(!empty($site_logo_element), 'The branding block logo was found.');
+    $this->assertTrue(!empty($site_name_element), 'The branding block site name was found.');
+    $this->assertTrue(!empty($site_slogan_element), 'The branding block slogan was found.');
+    $this->assertCacheTag('config:system.site');
+
+    // Turn just the logo off.
+    $this->config('block.block.site-branding')
+      ->set('settings.use_site_logo', 0)
+      ->save();
+    $this->drupalGet('');
+    $site_logo_element = $this->xpath($site_logo_xpath);
+    $site_name_element = $this->xpath($site_name_xpath);
+    $site_slogan_element = $this->xpath($site_slogan_xpath);
+    // Re-test all branding elements.
+    $this->assertTrue(empty($site_logo_element), 'The branding block logo was disabled.');
+    $this->assertTrue(!empty($site_name_element), 'The branding block site name was found.');
+    $this->assertTrue(!empty($site_slogan_element), 'The branding block slogan was found.');
+    $this->assertCacheTag('config:system.site');
+
+    // Turn just the site name off.
+    $this->config('block.block.site-branding')
+      ->set('settings.use_site_logo', 1)
+      ->set('settings.use_site_name', 0)
+      ->save();
+    $this->drupalGet('');
+    $site_logo_element = $this->xpath($site_logo_xpath);
+    $site_name_element = $this->xpath($site_name_xpath);
+    $site_slogan_element = $this->xpath($site_slogan_xpath);
+    // Re-test all branding elements.
+    $this->assertTrue(!empty($site_logo_element), 'The branding block logo was found.');
+    $this->assertTrue(empty($site_name_element), 'The branding block site name was disabled.');
+    $this->assertTrue(!empty($site_slogan_element), 'The branding block slogan was found.');
+    $this->assertCacheTag('config:system.site');
+
+    // Turn just the site slogan off.
+    $this->config('block.block.site-branding')
+      ->set('settings.use_site_name', 1)
+      ->set('settings.use_site_slogan', 0)
+      ->save();
+    $this->drupalGet('');
+    $site_logo_element = $this->xpath($site_logo_xpath);
+    $site_name_element = $this->xpath($site_name_xpath);
+    $site_slogan_element = $this->xpath($site_slogan_xpath);
+    // Re-test all branding elements.
+    $this->assertTrue(!empty($site_logo_element), 'The branding block logo was found.');
+    $this->assertTrue(!empty($site_name_element), 'The branding block site name was found.');
+    $this->assertTrue(empty($site_slogan_element), 'The branding block slogan was disabled.');
+    $this->assertCacheTag('config:system.site');
+
+    // Turn the site name and the site slogan off.
+    $this->config('block.block.site-branding')
+      ->set('settings.use_site_name', 0)
+      ->set('settings.use_site_slogan', 0)
+      ->save();
+    $this->drupalGet('');
+    $site_logo_element = $this->xpath($site_logo_xpath);
+    $site_name_element = $this->xpath($site_name_xpath);
+    $site_slogan_element = $this->xpath($site_slogan_xpath);
+    // Re-test all branding elements.
+    $this->assertTrue(!empty($site_logo_element), 'The branding block logo was found.');
+    $this->assertTrue(empty($site_name_element), 'The branding block site name was disabled.');
+    $this->assertTrue(empty($site_slogan_element), 'The branding block slogan was disabled.');
+    $this->assertCacheTag('config:system.site');
+  }
+
+}

core/modules/block/src/Tests/BlockTemplateSuggestionsTest.php

@@ -0,0 +1,53 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Tests\BlockTemplateSuggestionsTest.
+ */
+
+namespace Drupal\block\Tests;
+
+use Drupal\simpletest\WebTestBase;
+
+/**
+ * Tests the block_theme_suggestions_block() function.
+ *
+ * @group block
+ */
+class BlockTemplateSuggestionsTest extends WebTestBase {
+
+  /**
+   * Modules to install.
+   *
+   * @var array
+   */
+  public static $modules = array('block');
+
+  /**
+   * Tests template suggestions from block_theme_suggestions_block().
+   */
+  function testBlockThemeHookSuggestions() {
+    // Define a block with a derivative to be preprocessed, which includes both
+    // an underscore (not transformed) and a hyphen (transformed to underscore),
+    // and generates possibilities for each level of derivative.
+    // @todo Clarify this comment.
+    /** @var \Drupal\block\BlockInterface $block */
+    $block = entity_create('block', array(
+      'plugin' => 'system_menu_block:admin',
+      'region' => 'footer',
+      'id' => 'machinename',
+    ));
+
+    $variables = array();
+    $plugin = $block->getPlugin();
+    $variables['elements']['#configuration'] = $plugin->getConfiguration();
+    $variables['elements']['#plugin_id'] = $plugin->getPluginId();
+    $variables['elements']['#id'] = $block->id();
+    $variables['elements']['#base_plugin_id'] = $plugin->getBaseId();
+    $variables['elements']['#derivative_plugin_id'] = $plugin->getDerivativeId();
+    $variables['elements']['content'] = array();
+    $suggestions = block_theme_suggestions_block($variables);
+    $this->assertEqual($suggestions, array('block__system', 'block__system_menu_block', 'block__system_menu_block__admin', 'block__machinename'));
+  }
+
+}

core/modules/block/src/Tests/BlockTest.php

@@ -0,0 +1,441 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Tests\BlockTest.
+ */
+
+namespace Drupal\block\Tests;
+
+use Drupal\Component\Utility\Html;
+use Drupal\simpletest\WebTestBase;
+use Drupal\block\Entity\Block;
+use Drupal\user\RoleInterface;
+
+/**
+ * Tests basic block functionality.
+ *
+ * @group block
+ */
+class BlockTest extends BlockTestBase {
+
+  /**
+   * Tests block visibility.
+   */
+  function testBlockVisibility() {
+    $block_name = 'system_powered_by_block';
+    // Create a random title for the block.
+    $title = $this->randomMachineName(8);
+    // Enable a standard block.
+    $default_theme = $this->config('system.theme')->get('default');
+    $edit = array(
+      'id' => strtolower($this->randomMachineName(8)),
+      'region' => 'sidebar_first',
+      'settings[label]' => $title,
+    );
+    // Set the block to be hidden on any user path, and to be shown only to
+    // authenticated users.
+    $edit['visibility[request_path][pages]'] = '/user*';
+    $edit['visibility[request_path][negate]'] = TRUE;
+    $edit['visibility[user_role][roles][' . RoleInterface::AUTHENTICATED_ID . ']'] = TRUE;
+    $this->drupalGet('admin/structure/block/add/' . $block_name . '/' . $default_theme);
+    $this->assertFieldChecked('edit-visibility-request-path-negate-0');
+
+    $this->drupalPostForm(NULL, $edit, t('Save block'));
+    $this->assertText('The block configuration has been saved.', 'Block was saved');
+
+    $this->clickLink('Configure');
+    $this->assertFieldChecked('edit-visibility-request-path-negate-1');
+
+    $this->drupalGet('');
+    $this->assertText($title, 'Block was displayed on the front page.');
+
+    $this->drupalGet('user');
+    $this->assertNoText($title, 'Block was not displayed according to block visibility rules.');
+
+    // Confirm that the block is not displayed to anonymous users.
+    $this->drupalLogout();
+    $this->drupalGet('');
+    $this->assertNoText($title, 'Block was not displayed to anonymous users.');
+
+    // Confirm that an empty block is not displayed.
+    $this->assertNoText('Powered by Drupal', 'Empty block not displayed.');
+    $this->assertNoRaw('sidebar-first', 'Empty sidebar-first region is not displayed.');
+  }
+
+  /**
+   * Tests that visibility can be properly toggled.
+   */
+  public function testBlockToggleVisibility() {
+    $block_name = 'system_powered_by_block';
+    // Create a random title for the block.
+    $title = $this->randomMachineName(8);
+    // Enable a standard block.
+    $default_theme = $this->config('system.theme')->get('default');
+    $edit = array(
+      'id' => strtolower($this->randomMachineName(8)),
+      'region' => 'sidebar_first',
+      'settings[label]' => $title,
+    );
+    $block_id = $edit['id'];
+    // Set the block to be shown only to authenticated users.
+    $edit['visibility[user_role][roles][' . RoleInterface::AUTHENTICATED_ID . ']'] = TRUE;
+    $this->drupalPostForm('admin/structure/block/add/' . $block_name . '/' . $default_theme, $edit, t('Save block'));
+    $this->clickLink('Configure');
+    $this->assertFieldChecked('edit-visibility-user-role-roles-authenticated');
+
+    $edit = [
+      'visibility[user_role][roles][' . RoleInterface::AUTHENTICATED_ID . ']' => FALSE,
+    ];
+    $this->drupalPostForm(NULL, $edit, 'Save block');
+    $this->clickLink('Configure');
+    $this->assertNoFieldChecked('edit-visibility-user-role-roles-authenticated');
+
+    // Ensure that no visibility is configured.
+    /** @var \Drupal\block\BlockInterface $block */
+    $block = Block::load($block_id);
+    $visibility_config = $block->getVisibilityConditions()->getConfiguration();
+    $this->assertIdentical([], $visibility_config);
+    $this->assertIdentical([], $block->get('visibility'));
+  }
+
+  /**
+   * Test block visibility when leaving "pages" textarea empty.
+   */
+  function testBlockVisibilityListedEmpty() {
+    $block_name = 'system_powered_by_block';
+    // Create a random title for the block.
+    $title = $this->randomMachineName(8);
+    // Enable a standard block.
+    $default_theme = $this->config('system.theme')->get('default');
+    $edit = array(
+      'id' => strtolower($this->randomMachineName(8)),
+      'region' => 'sidebar_first',
+      'settings[label]' => $title,
+      'visibility[request_path][negate]' => TRUE,
+    );
+    // Set the block to be hidden on any user path, and to be shown only to
+    // authenticated users.
+    $this->drupalPostForm('admin/structure/block/add/' . $block_name . '/' . $default_theme, $edit, t('Save block'));
+    $this->assertText('The block configuration has been saved.', 'Block was saved');
+
+    $this->drupalGet('user');
+    $this->assertNoText($title, 'Block was not displayed according to block visibility rules.');
+
+    $this->drupalGet('USER');
+    $this->assertNoText($title, 'Block was not displayed according to block visibility rules regardless of path case.');
+
+    // Confirm that the block is not displayed to anonymous users.
+    $this->drupalLogout();
+    $this->drupalGet('');
+    $this->assertNoText($title, 'Block was not displayed to anonymous users on the front page.');
+  }
+
+  /**
+   * Test configuring and moving a module-define block to specific regions.
+   */
+  function testBlock() {
+    // Select the 'Powered by Drupal' block to be configured and moved.
+    $block = array();
+    $block['id'] = 'system_powered_by_block';
+    $block['settings[label]'] = $this->randomMachineName(8);
+    $block['theme'] = $this->config('system.theme')->get('default');
+    $block['region'] = 'header';
+
+    // Set block title to confirm that interface works and override any custom titles.
+    $this->drupalPostForm('admin/structure/block/add/' . $block['id'] . '/' . $block['theme'], array('settings[label]' => $block['settings[label]'], 'id' => $block['id'], 'region' => $block['region']), t('Save block'));
+    $this->assertText(t('The block configuration has been saved.'), 'Block title set.');
+    // Check to see if the block was created by checking its configuration.
+    $instance = Block::load($block['id']);
+
+    $this->assertEqual($instance->label(), $block['settings[label]'], 'Stored block title found.');
+
+    // Check whether the block can be moved to all available regions.
+    foreach ($this->regions as $region) {
+      $this->moveBlockToRegion($block, $region);
+    }
+
+    // Set the block to the disabled region.
+    $edit = array();
+    $edit['blocks[' . $block['id'] . '][region]'] = -1;
+    $this->drupalPostForm('admin/structure/block', $edit, t('Save blocks'));
+
+    // Confirm that the block is now listed as disabled.
+    $this->assertText(t('The block settings have been updated.'), 'Block successfully move to disabled region.');
+
+    // Confirm that the block instance title and markup are not displayed.
+    $this->drupalGet('node');
+    $this->assertNoText(t($block['settings[label]']));
+    // Check for <div id="block-my-block-instance-name"> if the machine name
+    // is my_block_instance_name.
+    $xpath = $this->buildXPathQuery('//div[@id=:id]/*', array(':id' => 'block-' . str_replace('_', '-', strtolower($block['id']))));
+    $this->assertNoFieldByXPath($xpath, FALSE, 'Block found in no regions.');
+
+    // Test deleting the block from the edit form.
+    $this->drupalGet('admin/structure/block/manage/' . $block['id']);
+    $this->clickLink(t('Delete'));
+    $this->assertRaw(t('Are you sure you want to delete the block %name?', array('%name' => $block['settings[label]'])));
+    $this->drupalPostForm(NULL, array(), t('Delete'));
+    $this->assertRaw(t('The block %name has been deleted.', array('%name' => $block['settings[label]'])));
+
+    // Test deleting a block via "Configure block" link.
+    $block = $this->drupalPlaceBlock('system_powered_by_block');
+    $this->drupalGet('admin/structure/block/manage/' . $block->id(), array('query' => array('destination' => 'admin')));
+    $this->clickLink(t('Delete'));
+    $this->assertRaw(t('Are you sure you want to delete the block %name?', array('%name' => $block->label())));
+    $this->drupalPostForm(NULL, array(), t('Delete'));
+    $this->assertRaw(t('The block %name has been deleted.', array('%name' => $block->label())));
+    $this->assertUrl('admin');
+    $this->assertNoRaw($block->id());
+  }
+
+  /**
+   * Tests that the block form has a theme selector when not passed via the URL.
+   */
+  public function testBlockThemeSelector() {
+    // Install all themes.
+    \Drupal::service('theme_handler')->install(array('bartik', 'seven'));
+    $theme_settings = $this->config('system.theme');
+    foreach (array('bartik', 'classy', 'seven') as $theme) {
+      $this->drupalGet('admin/structure/block/list/' . $theme);
+      $this->assertTitle(t('Block layout') . ' | Drupal');
+      // Select the 'Powered by Drupal' block to be placed.
+      $block = array();
+      $block['id'] = strtolower($this->randomMachineName());
+      $block['theme'] = $theme;
+      $block['region'] = 'content';
+      $this->drupalPostForm('admin/structure/block/add/system_powered_by_block', $block, t('Save block'));
+      $this->assertText(t('The block configuration has been saved.'));
+      $this->assertUrl('admin/structure/block/list/' . $theme . '?block-placement=' . Html::getClass($block['id']));
+
+      // Set the default theme and ensure the block is placed.
+      $theme_settings->set('default', $theme)->save();
+      $this->drupalGet('');
+      $elements = $this->xpath('//div[@id = :id]', array(':id' => Html::getUniqueId('block-' . $block['id'])));
+      $this->assertTrue(!empty($elements), 'The block was found.');
+    }
+  }
+
+  /**
+   * Test block display of theme titles.
+   */
+  function testThemeName() {
+    // Enable the help block.
+    $this->drupalPlaceBlock('help_block', array('region' => 'help'));
+    // Explicitly set the default and admin themes.
+    $theme = 'block_test_specialchars_theme';
+    \Drupal::service('theme_handler')->install(array($theme));
+    \Drupal::service('router.builder')->rebuild();
+    $this->drupalGet('admin/structure/block');
+    $this->assertEscaped('<"Cat" & \'Mouse\'>');
+    $this->drupalGet('admin/structure/block/list/block_test_specialchars_theme');
+    $this->assertEscaped('Demonstrate block regions (<"Cat" & \'Mouse\'>)');
+  }
+
+  /**
+   * Test block title display settings.
+   */
+  function testHideBlockTitle() {
+    $block_name = 'system_powered_by_block';
+    // Create a random title for the block.
+    $title = $this->randomMachineName(8);
+    $id = strtolower($this->randomMachineName(8));
+    // Enable a standard block.
+    $default_theme = $this->config('system.theme')->get('default');
+    $edit = array(
+      'id' => $id,
+      'region' => 'sidebar_first',
+      'settings[label]' => $title,
+    );
+    $this->drupalPostForm('admin/structure/block/add/' . $block_name . '/' . $default_theme, $edit, t('Save block'));
+    $this->assertText('The block configuration has been saved.', 'Block was saved');
+
+    $this->drupalGet('user');
+    $this->assertText($title, 'Block title was displayed by default.');
+
+    $edit = array(
+      'settings[label_display]' => FALSE,
+    );
+    $this->drupalPostForm('admin/structure/block/manage/' . $id, $edit, t('Save block'));
+    $this->assertText('The block configuration has been saved.', 'Block was saved');
+
+    $this->drupalGet('admin/structure/block/manage/' . $id);
+    $this->assertNoFieldChecked('edit-settings-label-display', 'The display_block option has the correct default value on the configuration form.');
+
+    $this->drupalGet('user');
+    $this->assertNoText($title, 'Block title was not displayed when hidden.');
+  }
+
+  /**
+   * Moves a block to a given region via the UI and confirms the result.
+   *
+   * @param array $block
+   *   An array of information about the block, including the following keys:
+   *   - module: The module providing the block.
+   *   - title: The title of the block.
+   *   - delta: The block's delta key.
+   * @param string $region
+   *   The machine name of the theme region to move the block to, for example
+   *   'header' or 'sidebar_first'.
+   */
+  function moveBlockToRegion(array $block, $region) {
+    // Set the created block to a specific region.
+    $block += array('theme' => $this->config('system.theme')->get('default'));
+    $edit = array();
+    $edit['blocks[' . $block['id'] . '][region]'] = $region;
+    $this->drupalPostForm('admin/structure/block', $edit, t('Save blocks'));
+
+    // Confirm that the block was moved to the proper region.
+    $this->assertText(t('The block settings have been updated.'), format_string('Block successfully moved to %region_name region.', array( '%region_name' => $region)));
+
+    // Confirm that the block is being displayed.
+    $this->drupalGet('');
+    $this->assertText(t($block['settings[label]']), 'Block successfully being displayed on the page.');
+
+    // Confirm that the custom block was found at the proper region.
+    $xpath = $this->buildXPathQuery('//div[@class=:region-class]//div[@id=:block-id]/*', array(
+      ':region-class' => 'region region-' . Html::getClass($region),
+      ':block-id' => 'block-' . str_replace('_', '-', strtolower($block['id'])),
+    ));
+    $this->assertFieldByXPath($xpath, NULL, t('Block found in %region_name region.', array('%region_name' => Html::getClass($region))));
+  }
+
+  /**
+   * Test that cache tags are properly set and bubbled up to the page cache.
+   *
+   * Verify that invalidation of these cache tags works:
+   * - "block:<block ID>"
+   * - "block_plugin:<block plugin ID>"
+   */
+  public function testBlockCacheTags() {
+    // The page cache only works for anonymous users.
+    $this->drupalLogout();
+
+    // Enable page caching.
+    $config = $this->config('system.performance');
+    $config->set('cache.page.max_age', 300);
+    $config->save();
+
+    // Place the "Powered by Drupal" block.
+    $block = $this->drupalPlaceBlock('system_powered_by_block', array('id' => 'powered'));
+
+    // Prime the page cache.
+    $this->drupalGet('<front>');
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'MISS');
+
+    // Verify a cache hit, but also the presence of the correct cache tags in
+    // both the page and block caches.
+    $this->drupalGet('<front>');
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'HIT');
+    $cid_parts = array(\Drupal::url('<front>', array(), array('absolute' => TRUE)), 'html');
+    $cid = implode(':', $cid_parts);
+    $cache_entry = \Drupal::cache('render')->get($cid);
+    $expected_cache_tags = array(
+      'config:block_list',
+      'block_view',
+      'config:block.block.powered',
+      'rendered',
+    );
+    sort($expected_cache_tags);
+    $this->assertIdentical($cache_entry->tags, $expected_cache_tags);
+    $cache_entry = \Drupal::cache('render')->get('entity_view:block:powered:en:classy');
+    $expected_cache_tags = array(
+      'block_view',
+      'config:block.block.powered',
+      'rendered',
+    );
+    sort($expected_cache_tags);
+    $this->assertIdentical($cache_entry->tags, $expected_cache_tags);
+
+    // The "Powered by Drupal" block is modified; verify a cache miss.
+    $block->setRegion('content');
+    $block->save();
+    $this->drupalGet('<front>');
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'MISS');
+
+    // Now we should have a cache hit again.
+    $this->drupalGet('<front>');
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'HIT');
+
+    // Place the "Powered by Drupal" block another time; verify a cache miss.
+    $block_2 = $this->drupalPlaceBlock('system_powered_by_block', array('id' => 'powered-2'));
+    $this->drupalGet('<front>');
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'MISS');
+
+    // Verify a cache hit, but also the presence of the correct cache tags.
+    $this->drupalGet('<front>');
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'HIT');
+    $cid_parts = array(\Drupal::url('<front>', array(), array('absolute' => TRUE)), 'html');
+    $cid = implode(':', $cid_parts);
+    $cache_entry = \Drupal::cache('render')->get($cid);
+    $expected_cache_tags = array(
+      'config:block_list',
+      'block_view',
+      'config:block.block.powered',
+      'config:block.block.powered-2',
+      'rendered',
+    );
+    sort($expected_cache_tags);
+    $this->assertEqual($cache_entry->tags, $expected_cache_tags);
+    $expected_cache_tags = array(
+      'block_view',
+      'config:block.block.powered',
+      'rendered',
+    );
+    sort($expected_cache_tags);
+    $cache_entry = \Drupal::cache('render')->get('entity_view:block:powered:en:classy');
+    $this->assertIdentical($cache_entry->tags, $expected_cache_tags);
+    $expected_cache_tags = array(
+      'block_view',
+      'config:block.block.powered-2',
+      'rendered',
+    );
+    sort($expected_cache_tags);
+    $cache_entry = \Drupal::cache('render')->get('entity_view:block:powered-2:en:classy');
+    $this->assertIdentical($cache_entry->tags, $expected_cache_tags);
+
+    // Now we should have a cache hit again.
+    $this->drupalGet('<front>');
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'HIT');
+
+    // Delete the "Powered by Drupal" blocks; verify a cache miss.
+    entity_delete_multiple('block', array('powered', 'powered-2'));
+    $this->drupalGet('<front>');
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'MISS');
+  }
+
+  /**
+   * Tests that uninstalling a theme removes its block configuration.
+   */
+  public function testUninstallTheme() {
+    /** @var \Drupal\Core\Extension\ThemeHandlerInterface $theme_handler */
+    $theme_handler = \Drupal::service('theme_handler');
+
+    $theme_handler->install(['seven']);
+    $theme_handler->setDefault('seven');
+    $block = $this->drupalPlaceBlock('system_powered_by_block', ['theme' => 'seven', 'region' => 'help']);
+    $this->drupalGet('<front>');
+    $this->assertText('Powered by Drupal');
+
+    $theme_handler->setDefault('classy');
+    $theme_handler->uninstall(['seven']);
+
+    // Ensure that the block configuration does not exist anymore.
+    $this->assertIdentical(NULL, Block::load($block->id()));
+  }
+
+  /**
+   * Tests the block access.
+   */
+  public function testBlockAccess() {
+    $this->drupalPlaceBlock('test_access', ['region' => 'help']);
+
+    $this->drupalGet('<front>');
+    $this->assertNoText('Hello test world');
+
+    \Drupal::state()->set('test_block_access', TRUE);
+    $this->drupalGet('<front>');
+    $this->assertText('Hello test world');
+  }
+
+}

core/modules/block/src/Tests/BlockTestBase.php

@@ -0,0 +1,74 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Tests\BlockTestBase.
+ */
+
+namespace Drupal\block\Tests;
+
+use Drupal\simpletest\WebTestBase;
+
+/**
+ * Provides setup and helper methods for block module tests.
+ */
+abstract class BlockTestBase extends WebTestBase {
+
+  /**
+   * Modules to install.
+   *
+   * @var array
+   */
+  public static $modules = array('block', 'filter', 'test_page_test', 'help', 'block_test');
+
+  /**
+   * A list of theme regions to test.
+   *
+   * @var array
+   */
+  protected $regions;
+
+  /**
+   * A test user with administrative privileges.
+   *
+   * @var \Drupal\user\UserInterface
+   */
+  protected $adminUser;
+
+  protected function setUp() {
+    parent::setUp();
+
+    // Use the test page as the front page.
+    $this->config('system.site')->set('page.front', '/test-page')->save();
+
+    // Create Full HTML text format.
+    $full_html_format = entity_create('filter_format', array(
+      'format' => 'full_html',
+      'name' => 'Full HTML',
+    ));
+    $full_html_format->save();
+
+    // Create and log in an administrative user having access to the Full HTML
+    // text format.
+    $this->adminUser = $this->drupalCreateUser(array(
+      'administer blocks',
+      $full_html_format->getPermissionName(),
+      'access administration pages',
+    ));
+    $this->drupalLogin($this->adminUser);
+
+    // Define the existing regions.
+    $this->regions = array(
+      'header',
+      'sidebar_first',
+      'content',
+      'sidebar_second',
+      'footer',
+    );
+    $block_storage = $this->container->get('entity.manager')->getStorage('block');
+    $blocks = $block_storage->loadByProperties(array('theme' => $this->config('system.theme')->get('default')));
+    foreach ($blocks as $block) {
+      $block->delete();
+    }
+  }
+}

core/modules/block/src/Tests/BlockTitleXSSTest.php

@@ -0,0 +1,46 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Tests\BlockTitleXSSTest.
+ */
+
+namespace Drupal\block\Tests;
+
+use Drupal\simpletest\WebTestBase;
+
+/**
+ * Tests block XSS in title.
+ *
+ * @group block
+ */
+class BlockTitleXSSTest extends WebTestBase {
+
+  /**
+   * Modules to install.
+   *
+   * @var array
+   */
+  public static $modules = array('block', 'block_test');
+
+  protected function setUp() {
+    parent::setUp();
+
+    $this->drupalPlaceBlock('test_xss_title', array('label' => '<script>alert("XSS label");</script>'));
+  }
+
+  /**
+   * Test XSS in title.
+   */
+  function testXSSInTitle() {
+    \Drupal::state()->set('block_test.content', $this->randomMachineName());
+    $this->drupalGet('');
+    $this->assertNoRaw('<script>alert("XSS label");</script>', 'The block title was properly sanitized when rendered.');
+
+    $this->drupalLogin($this->drupalCreateUser(array('administer blocks', 'access administration pages')));
+    $default_theme = $this->config('system.theme')->get('default');
+    $this->drupalGet('admin/structure/block/list/' . $default_theme);
+    $this->assertNoRaw("<script>alert('XSS subject');</script>", 'The block title was properly sanitized in Block Plugin UI Admin page.');
+  }
+
+}

core/modules/block/src/Tests/BlockUiTest.php

@@ -0,0 +1,211 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Tests\BlockUiTest.
+ */
+
+namespace Drupal\block\Tests;
+
+use Drupal\Component\Utility\Html;
+use Drupal\simpletest\WebTestBase;
+
+/**
+ * Tests that the block configuration UI exists and stores data correctly.
+ *
+ * @group block
+ */
+class BlockUiTest extends WebTestBase {
+
+  /**
+   * Modules to install.
+   *
+   * @var array
+   */
+  public static $modules = array('block', 'block_test', 'help');
+
+  protected $regions;
+
+  /**
+   * The submitted block values used by this test.
+   *
+   * @var array
+   */
+  protected $blockValues;
+
+  /**
+   * The block entities used by this test.
+   *
+   * @var \Drupal\block\BlockInterface[]
+   */
+  protected $blocks;
+
+  /**
+   * An administrative user to configure the test environment.
+   */
+  protected $adminUser;
+
+  protected function setUp() {
+    parent::setUp();
+    // Create and log in an administrative user.
+    $this->adminUser = $this->drupalCreateUser(array(
+      'administer blocks',
+      'access administration pages',
+    ));
+    $this->drupalLogin($this->adminUser);
+
+    // Enable some test blocks.
+    $this->blockValues = array(
+      array(
+        'label' => 'Tools',
+        'tr' => '5',
+        'plugin_id' => 'system_menu_block:tools',
+        'settings' => array('region' => 'sidebar_second', 'id' => 'tools'),
+        'test_weight' => '-1',
+      ),
+      array(
+        'label' => 'Powered by Drupal',
+        'tr' => '16',
+        'plugin_id' => 'system_powered_by_block',
+        'settings' => array('region' => 'footer', 'id' => 'powered'),
+        'test_weight' => '0',
+      ),
+    );
+    $this->blocks = array();
+    foreach ($this->blockValues as $values) {
+      $this->blocks[] = $this->drupalPlaceBlock($values['plugin_id'], $values['settings']);
+    }
+  }
+
+  /**
+   * Test block demo page exists and functions correctly.
+   */
+  public function testBlockDemoUiPage() {
+    $this->drupalPlaceBlock('help_block', array('region' => 'help'));
+    $this->drupalGet('admin/structure/block');
+    $this->clickLink(t('Demonstrate block regions (@theme)', array('@theme' => 'Classy')));
+    $elements = $this->xpath('//div[contains(@class, "region-highlighted")]/div[contains(@class, "block-region") and contains(text(), :title)]', array(':title' => 'Highlighted'));
+    $this->assertTrue(!empty($elements), 'Block demo regions are shown.');
+  }
+
+  /**
+   * Test block admin page exists and functions correctly.
+   */
+  function testBlockAdminUiPage() {
+    // Visit the blocks admin ui.
+    $this->drupalGet('admin/structure/block');
+    // Look for the blocks table.
+    $blocks_table = $this->xpath("//table[@id='blocks']");
+    $this->assertTrue(!empty($blocks_table), 'The blocks table is being rendered.');
+    // Look for test blocks in the table.
+    foreach ($this->blockValues as $delta => $values) {
+      $block = $this->blocks[$delta];
+      $label = $block->label();
+      $element = $this->xpath('//*[@id="blocks"]/tbody/tr[' . $values['tr'] . ']/td[1]/text()');
+      $this->assertTrue((string) $element[0] == $label, 'The "' . $label . '" block title is set inside the ' . $values['settings']['region'] . ' region.');
+      // Look for a test block region select form element.
+      $this->assertField('blocks[' . $values['settings']['id'] . '][region]', 'The block "' . $values['label'] . '" has a region assignment field.');
+      // Move the test block to the header region.
+      $edit['blocks[' . $values['settings']['id'] . '][region]'] = 'header';
+      // Look for a test block weight select form element.
+      $this->assertField('blocks[' . $values['settings']['id'] . '][weight]', 'The block "' . $values['label'] . '" has a weight assignment field.');
+      // Change the test block's weight.
+      $edit['blocks[' . $values['settings']['id'] . '][weight]'] = $values['test_weight'];
+    }
+    $this->drupalPostForm('admin/structure/block', $edit, t('Save blocks'));
+    foreach ($this->blockValues as $values) {
+      // Check if the region and weight settings changes have persisted.
+      $this->assertOptionSelected(
+        'edit-blocks-' . $values['settings']['id']  . '-region',
+        'header',
+        'The block "' . $label . '" has the correct region assignment (header).'
+      );
+      $this->assertOptionSelected(
+        'edit-blocks-' . $values['settings']['id']  . '-weight',
+        $values['test_weight'],
+        'The block "' . $label . '" has the correct weight assignment (' . $values['test_weight'] . ').'
+      );
+    }
+  }
+
+  /**
+   * Tests the block categories on the listing page.
+   */
+  public function testCandidateBlockList() {
+    $arguments = array(
+      ':ul_class' => 'block-list',
+      ':li_class' => 'test-block-instantiation',
+      ':href' => 'admin/structure/block/add/test_block_instantiation/classy',
+      ':text' => 'Display message',
+    );
+
+    $this->drupalGet('admin/structure/block');
+    $elements = $this->xpath('//details[@id="edit-category-block-test"]//ul[contains(@class, :ul_class)]/li[contains(@class, :li_class)]/a[contains(@href, :href) and text()=:text]', $arguments);
+    $this->assertTrue(!empty($elements), 'The test block appears in the category for its module.');
+
+    // Trigger the custom category addition in block_test_block_alter().
+    $this->container->get('state')->set('block_test_info_alter', TRUE);
+    $this->container->get('plugin.manager.block')->clearCachedDefinitions();
+
+    $this->drupalGet('admin/structure/block');
+    $elements = $this->xpath('//details[@id="edit-category-custom-category"]//ul[contains(@class, :ul_class)]/li[contains(@class, :li_class)]/a[contains(@href, :href) and text()=:text]', $arguments);
+    $this->assertTrue(!empty($elements), 'The test block appears in a custom category controlled by block_test_block_alter().');
+  }
+
+  /**
+   * Tests the behavior of context-aware blocks.
+   */
+  public function testContextAwareBlocks() {
+    $arguments = array(
+      ':ul_class' => 'block-list',
+      ':li_class' => 'test-context-aware',
+      ':href' => 'admin/structure/block/add/test_context_aware/classy',
+      ':text' => 'Test context-aware block',
+    );
+
+    $this->drupalGet('admin/structure/block');
+    $elements = $this->xpath('//details[@id="edit-category-block-test"]//ul[contains(@class, :ul_class)]/li[contains(@class, :li_class)]/a[contains(@href, :href) and text()=:text]', $arguments);
+    $this->assertTrue(empty($elements), 'The context-aware test block does not appear.');
+    $definition = \Drupal::service('plugin.manager.block')->getDefinition('test_context_aware');
+    $this->assertTrue(!empty($definition), 'The context-aware test block exists.');
+  }
+
+  /**
+   * Tests that the BlockForm populates machine name correctly.
+   */
+  public function testMachineNameSuggestion() {
+    $url = 'admin/structure/block/add/test_block_instantiation/classy';
+    $this->drupalGet($url);
+    $this->assertFieldByName('id', 'displaymessage', 'Block form uses raw machine name suggestion when no instance already exists.');
+    $this->drupalPostForm($url, array(), 'Save block');
+
+    // Now, check to make sure the form starts by autoincrementing correctly.
+    $this->drupalGet($url);
+    $this->assertFieldByName('id', 'displaymessage_2', 'Block form appends _2 to plugin-suggested machine name when an instance already exists.');
+    $this->drupalPostForm($url, array(), 'Save block');
+
+    // And verify that it continues working beyond just the first two.
+    $this->drupalGet($url);
+    $this->assertFieldByName('id', 'displaymessage_3', 'Block form appends _3 to plugin-suggested machine name when two instances already exist.');
+  }
+
+  /**
+   * Tests the block placement indicator.
+   */
+  public function testBlockPlacementIndicator() {
+    // Select the 'Powered by Drupal' block to be placed.
+    $block = array();
+    $block['id'] = strtolower($this->randomMachineName());
+    $block['theme'] = 'classy';
+    $block['region'] = 'content';
+
+    // After adding a block, it will indicate which block was just added.
+    $this->drupalPostForm('admin/structure/block/add/system_powered_by_block', $block, t('Save block'));
+    $this->assertUrl('admin/structure/block/list/classy?block-placement=' . Html::getClass($block['id']));
+
+    // Resaving the block page will remove the block indicator.
+    $this->drupalPostForm(NULL, array(), t('Save blocks'));
+    $this->assertUrl('admin/structure/block/list/classy');
+  }
+
+}

core/modules/block/src/Tests/BlockViewBuilderTest.php

@@ -0,0 +1,271 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Tests\BlockViewBuilderTest.
+ */
+
+namespace Drupal\block\Tests;
+
+use Drupal\Component\Utility\Html;
+use Drupal\Core\Cache\Cache;
+use Drupal\Core\Cache\Context\UrlCacheContext;
+use Drupal\simpletest\KernelTestBase;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\RequestStack;
+use Drupal\block\Entity\Block;
+
+/**
+ * Tests the block view builder.
+ *
+ * @group block
+ */
+class BlockViewBuilderTest extends KernelTestBase {
+
+  /**
+   * Modules to install.
+   *
+   * @var array
+   */
+  public static $modules = array('block', 'block_test', 'system');
+
+  /**
+   * The block being tested.
+   *
+   * @var \Drupal\block\Entity\BlockInterface
+   */
+  protected $block;
+
+  /**
+   * The block storage.
+   *
+   * @var \Drupal\Core\Config\Entity\ConfigEntityStorageInterface
+   */
+  protected $controller;
+
+  /**
+   * The renderer.
+   *
+   * @var \Drupal\Core\Render\RendererInterface
+   */
+  protected $renderer;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+
+    $this->controller = $this->container
+      ->get('entity.manager')
+      ->getStorage('block');
+
+    \Drupal::state()->set('block_test.content', 'Llamas &gt; unicorns!');
+
+    // Create a block with only required values.
+    $this->block = $this->controller->create(array(
+      'id' => 'test_block',
+      'theme' => 'stark',
+      'plugin' => 'test_cache',
+    ));
+    $this->block->save();
+
+    $this->container->get('cache.render')->deleteAll();
+
+    $this->renderer = $this->container->get('renderer');
+  }
+
+  /**
+   * Tests the rendering of blocks.
+   */
+  public function testBasicRendering() {
+    \Drupal::state()->set('block_test.content', '');
+
+    $entity = $this->controller->create(array(
+      'id' => 'test_block1',
+      'theme' => 'stark',
+      'plugin' => 'test_html',
+    ));
+    $entity->save();
+
+    // Test the rendering of a block.
+    $entity = Block::load('test_block1');
+    $output = entity_view($entity, 'block');
+    $expected = array();
+    $expected[] = '<div id="block-test-block1">';
+    $expected[] = '  ';
+    $expected[] = '    ';
+    $expected[] = '      ';
+    $expected[] = '  </div>';
+    $expected[] = '';
+    $expected_output = implode("\n", $expected);
+    $this->assertEqual($this->renderer->renderRoot($output), $expected_output);
+
+    // Reset the HTML IDs so that the next render is not affected.
+    Html::resetSeenIds();
+
+    // Test the rendering of a block with a given title.
+    $entity = $this->controller->create(array(
+      'id' => 'test_block2',
+      'theme' => 'stark',
+      'plugin' => 'test_html',
+      'settings' => array(
+        'label' => 'Powered by Bananas',
+      ),
+    ));
+    $entity->save();
+    $output = entity_view($entity, 'block');
+    $expected = array();
+    $expected[] = '<div id="block-test-block2">';
+    $expected[] = '  ';
+    $expected[] = '      <h2>Powered by Bananas</h2>';
+    $expected[] = '    ';
+    $expected[] = '      ';
+    $expected[] = '  </div>';
+    $expected[] = '';
+    $expected_output = implode("\n", $expected);
+    $this->assertEqual($this->renderer->renderRoot($output), $expected_output);
+  }
+
+  /**
+   * Tests block render cache handling.
+   */
+  public function testBlockViewBuilderCache() {
+    // Verify cache handling for a non-empty block.
+    $this->verifyRenderCacheHandling();
+
+    // Create an empty block.
+    $this->block = $this->controller->create(array(
+      'id' => 'test_block',
+      'theme' => 'stark',
+      'plugin' => 'test_cache',
+    ));
+    $this->block->save();
+    \Drupal::state()->set('block_test.content', NULL);
+
+    // Verify cache handling for an empty block.
+    $this->verifyRenderCacheHandling();
+  }
+
+  /**
+   * Verifies render cache handling of the block being tested.
+   *
+   * @see ::testBlockViewBuilderCache()
+   */
+  protected function verifyRenderCacheHandling() {
+    // Force a request via GET so we can test the render cache.
+    $request = \Drupal::request();
+    $request_method = $request->server->get('REQUEST_METHOD');
+    $request->setMethod('GET');
+
+    // Test that a cache entry is created.
+    $build = $this->getBlockRenderArray();
+    $cid = 'entity_view:block:test_block:en:core';
+    $this->renderer->renderRoot($build);
+    $this->assertTrue($this->container->get('cache.render')->get($cid), 'The block render element has been cached.');
+
+    // Re-save the block and check that the cache entry has been deleted.
+    $this->block->save();
+    $this->assertFalse($this->container->get('cache.render')->get($cid), 'The block render cache entry has been cleared when the block was saved.');
+
+    // Rebuild the render array (creating a new cache entry in the process) and
+    // delete the block to check the cache entry is deleted.
+    unset($build['#printed']);
+    // Re-add the block because \Drupal\block\BlockViewBuilder::buildBlock()
+    // removes it.
+    $build['#block'] = $this->block;
+
+    $this->renderer->renderRoot($build);
+    $this->assertTrue($this->container->get('cache.render')->get($cid), 'The block render element has been cached.');
+    $this->block->delete();
+    $this->assertFalse($this->container->get('cache.render')->get($cid), 'The block render cache entry has been cleared when the block was deleted.');
+
+    // Restore the previous request method.
+    $request->setMethod($request_method);
+  }
+
+  /**
+   * Tests block view altering.
+   */
+  public function testBlockViewBuilderAlter() {
+    // Establish baseline.
+    $build = $this->getBlockRenderArray();
+    $this->assertIdentical($this->renderer->renderRoot($build), 'Llamas &gt; unicorns!');
+
+    // Enable the block view alter hook that adds a suffix, for basic testing.
+    \Drupal::state()->set('block_test_view_alter_suffix', TRUE);
+    Cache::invalidateTags($this->block->getCacheTags());
+    $build = $this->getBlockRenderArray();
+    $this->assertTrue(isset($build['#suffix']) && $build['#suffix'] === '<br>Goodbye!', 'A block with content is altered.');
+    $this->assertIdentical($this->renderer->renderRoot($build), 'Llamas &gt; unicorns!<br>Goodbye!');
+    \Drupal::state()->set('block_test_view_alter_suffix', FALSE);
+
+    // Force a request via GET so we can test the render cache.
+    $request = \Drupal::request();
+    $request_method = $request->server->get('REQUEST_METHOD');
+    $request->setMethod('GET');
+
+    \Drupal::state()->set('block_test.content', NULL);
+    Cache::invalidateTags($this->block->getCacheTags());
+
+    $default_keys = array('entity_view', 'block', 'test_block');
+    $default_tags = array('block_view', 'config:block.block.test_block');
+
+    // Advanced: cached block, but an alter hook adds an additional cache key.
+    $alter_add_key = $this->randomMachineName();
+    \Drupal::state()->set('block_test_view_alter_cache_key', $alter_add_key);
+    $cid = 'entity_view:block:test_block:' . $alter_add_key . ':en:core';
+    $expected_keys = array_merge($default_keys, array($alter_add_key));
+    $build = $this->getBlockRenderArray();
+    $this->assertIdentical($expected_keys, $build['#cache']['keys'], 'An altered cacheable block has the expected cache keys.');
+    $this->assertIdentical($this->renderer->renderRoot($build), '');
+    $cache_entry = $this->container->get('cache.render')->get($cid);
+    $this->assertTrue($cache_entry, 'The block render element has been cached with the expected cache ID.');
+    $expected_tags = array_merge($default_tags, ['rendered']);
+    sort($expected_tags);
+    $this->assertIdentical($cache_entry->tags, $expected_tags, 'The block render element has been cached with the expected cache tags.');
+    $this->container->get('cache.render')->delete($cid);
+
+    // Advanced: cached block, but an alter hook adds an additional cache tag.
+    $alter_add_tag = $this->randomMachineName();
+    \Drupal::state()->set('block_test_view_alter_cache_tag', $alter_add_tag);
+    $expected_tags = Cache::mergeTags($default_tags, array($alter_add_tag));
+    $build = $this->getBlockRenderArray();
+    sort($build['#cache']['tags']);
+    $this->assertIdentical($expected_tags, $build['#cache']['tags'], 'An altered cacheable block has the expected cache tags.');
+    $this->assertIdentical($this->renderer->renderRoot($build), '');
+    $cache_entry = $this->container->get('cache.render')->get($cid);
+    $this->assertTrue($cache_entry, 'The block render element has been cached with the expected cache ID.');
+    $expected_tags = array_merge($default_tags, [$alter_add_tag, 'rendered']);
+    sort($expected_tags);
+    $this->assertIdentical($cache_entry->tags, $expected_tags, 'The block render element has been cached with the expected cache tags.');
+    $this->container->get('cache.render')->delete($cid);
+
+    // Advanced: cached block, but an alter hook adds a #pre_render callback to
+    // alter the eventual content.
+    \Drupal::state()->set('block_test_view_alter_append_pre_render_prefix', TRUE);
+    $build = $this->getBlockRenderArray();
+    $this->assertFalse(isset($build['#prefix']), 'The appended #pre_render callback has not yet run before rendering.');
+    $this->assertIdentical($this->renderer->renderRoot($build), 'Hiya!<br>');
+    $this->assertTrue(isset($build['#prefix']) && $build['#prefix'] === 'Hiya!<br>', 'A cached block without content is altered.');
+
+    // Restore the previous request method.
+    $request->setMethod($request_method);
+  }
+
+  /**
+   * Get a fully built render array for a block.
+   *
+   * @return array
+   *   The render array.
+   */
+  protected function getBlockRenderArray() {
+    $build = $this->container->get('entity.manager')->getViewBuilder('block')->view($this->block, 'block');
+
+    // Mock the build array to not require the theme registry.
+    unset($build['#theme']);
+
+    return $build;
+  }
+
+}

core/modules/block/src/Tests/BlockXssTest.php

@@ -0,0 +1,94 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Tests\BlockXssTest.
+ */
+
+namespace Drupal\block\Tests;
+
+use Drupal\block_content\Entity\BlockContent;
+use Drupal\block_content\Entity\BlockContentType;
+use Drupal\Core\Url;
+use Drupal\simpletest\WebTestBase;
+use Drupal\system\Entity\Menu;
+use Drupal\views\Entity\View;
+
+/**
+ * Tests that the block module properly escapes block descriptions.
+ *
+ * @group block
+ */
+class BlockXssTest extends WebTestBase {
+
+  /**
+   * Modules to install.
+   *
+   * @var array
+   */
+  public static $modules = ['block', 'block_content', 'menu_ui', 'views'];
+
+  /**
+   * Tests various modules that provide blocks for XSS.
+   */
+  public function testBlockXss() {
+    $this->drupalLogin($this->rootUser);
+
+    $this->doViewTest();
+    $this->doMenuTest();
+    $this->doBlockContentTest();
+  }
+
+  /**
+   * Tests XSS coming from View block labels.
+   */
+  protected function doViewTest() {
+    $view = View::create([
+      'id' => $this->randomMachineName(),
+      'label' => '<script>alert("view");</script>',
+    ]);
+    $view->addDisplay('block');
+    $view->save();
+
+    $this->drupalGet(Url::fromRoute('block.admin_display'));
+    $this->clickLink('<script>alert("view");</script>');
+    $this->assertRaw('&lt;script&gt;alert(&quot;view&quot;);&lt;/script&gt;');
+    $this->assertNoRaw('<script>alert("view");</script>');
+  }
+
+  /**
+   * Tests XSS coming from Menu block labels.
+   */
+  protected function doMenuTest() {
+    Menu::create([
+      'id' => $this->randomMachineName(),
+      'label' => '<script>alert("menu");</script>',
+    ])->save();
+
+    $this->drupalGet(Url::fromRoute('block.admin_display'));
+    $this->clickLink('<script>alert("menu");</script>');
+    $this->assertRaw('&lt;script&gt;alert(&quot;menu&quot;);&lt;/script&gt;');
+    $this->assertNoRaw('<script>alert("menu");</script>');
+  }
+
+  /**
+   * Tests XSS coming from Block Content block info.
+   */
+  protected function doBlockContentTest() {
+    BlockContentType::create([
+      'id' => 'basic',
+      'label' => 'basic',
+      'revision' => TRUE,
+    ])->save();
+    BlockContent::create([
+      'type' => 'basic',
+      'info' => '<script>alert("block_content");</script>',
+    ])->save();
+
+    $this->drupalGet(Url::fromRoute('block.admin_display'));
+    $this->clickLink('<script>alert("block_content");</script>');
+    $this->assertRaw('&lt;script&gt;alert(&quot;block_content&quot;);&lt;/script&gt;');
+    $this->assertNoRaw('<script>alert("block_content");</script>');
+  }
+
+}

core/modules/block/src/Tests/NewDefaultThemeBlocksTest.php

@@ -0,0 +1,70 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Tests\NewDefaultThemeBlocksTest.
+ */
+
+namespace Drupal\block\Tests;
+
+use Drupal\simpletest\WebTestBase;
+
+/**
+ * Tests that the new default theme gets blocks.
+ *
+ * @group block
+ */
+class NewDefaultThemeBlocksTest extends WebTestBase {
+
+  /**
+   * Modules to install.
+   *
+   * @var array
+   */
+  public static $modules = array('block');
+
+  /**
+   * Check the enabled Bartik blocks are correctly copied over.
+   */
+  function testNewDefaultThemeBlocks() {
+    $default_theme = $this->config('system.theme')->get('default');
+
+    // Add two instances of the user login block.
+    $this->drupalPlaceBlock('user_login_block', array(
+      'id' => $default_theme . '_' . strtolower($this->randomMachineName(8)),
+    ));
+    $this->drupalPlaceBlock('user_login_block', array(
+      'id' => $default_theme . '_' . strtolower($this->randomMachineName(8)),
+    ));
+
+    // Add an instance of a different block.
+    $this->drupalPlaceBlock('system_powered_by_block', array(
+      'id' => $default_theme . '_' . strtolower($this->randomMachineName(8)),
+    ));
+
+    // Install a different theme.
+    $new_theme = 'bartik';
+    $this->assertFalse($new_theme == $default_theme, 'The new theme is different from the previous default theme.');
+    \Drupal::service('theme_handler')->install(array($new_theme));
+    $this->config('system.theme')
+      ->set('default', $new_theme)
+      ->save();
+
+    // Ensure that the new theme has all the blocks as the previous default.
+    $default_block_names = $this->container->get('entity.query')->get('block')
+      ->condition('theme', $default_theme)
+      ->execute();
+    $new_blocks = $this->container->get('entity.query')->get('block')
+      ->condition('theme', $new_theme)
+      ->execute();
+    $this->assertTrue(count($default_block_names) == count($new_blocks), 'The new default theme has the same number of blocks as the previous theme.');
+    foreach ($default_block_names as $default_block_name) {
+      // Remove the matching block from the list of blocks in the new theme.
+      // E.g., if the old theme has block.block.stark_admin,
+      // unset block.block.bartik_admin.
+      unset($new_blocks[str_replace($default_theme . '_', $new_theme . '_', $default_block_name)]);
+    }
+    $this->assertTrue(empty($new_blocks), 'The new theme has exactly the same blocks as the previous default theme.');
+  }
+
+}

core/modules/block/src/Tests/NonDefaultBlockAdminTest.php

@@ -0,0 +1,37 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Tests\NonDefaultBlockAdminTest.
+ */
+
+namespace Drupal\block\Tests;
+
+use Drupal\simpletest\WebTestBase;
+
+/**
+ * Tests the block administration page for a non-default theme.
+ *
+ * @group block
+ */
+class NonDefaultBlockAdminTest extends WebTestBase {
+
+  /**
+   * Modules to install.
+   *
+   * @var array
+   */
+  public static $modules = array('block');
+
+  /**
+   * Test non-default theme admin.
+   */
+  function testNonDefaultBlockAdmin() {
+    $admin_user = $this->drupalCreateUser(array('administer blocks', 'administer themes'));
+    $this->drupalLogin($admin_user);
+    $new_theme = 'bartik';
+    \Drupal::service('theme_handler')->install(array($new_theme));
+    $this->drupalGet('admin/structure/block/list/' . $new_theme);
+    $this->assertText('Bartik(' . t('active tab') . ')', 'Tab for non-default theme found.');
+  }
+}

core/modules/block/src/Tests/Views/DisplayBlockTest.php

@@ -0,0 +1,295 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Tests\Views\DisplayBlockTest.
+ */
+
+namespace Drupal\block\Tests\Views;
+
+use Drupal\Component\Serialization\Json;
+use Drupal\Component\Utility\Html;
+use Drupal\Component\Utility\SafeMarkup;
+use Drupal\views\Views;
+use Drupal\views\Tests\ViewTestBase;
+use Drupal\views\Tests\ViewTestData;
+use Drupal\Core\Template\Attribute;
+
+/**
+ * Tests the block display plugin.
+ *
+ * @group block
+ * @see \Drupal\block\Plugin\views\display\Block
+ */
+class DisplayBlockTest extends ViewTestBase {
+
+  /**
+   * Modules to install.
+   *
+   * @var array
+   */
+  public static $modules = array('node', 'block_test_views', 'test_page_test', 'contextual', 'views_ui');
+
+  /**
+   * Views used by this test.
+   *
+   * @var array
+   */
+  public static $testViews = array('test_view_block', 'test_view_block2');
+
+  protected function setUp() {
+    parent::setUp();
+
+    ViewTestData::createTestViews(get_class($this), array('block_test_views'));
+    $this->enableViewsTestModule();
+  }
+
+  /**
+   * Tests default and custom block categories.
+   */
+  public function testBlockCategory() {
+    $this->drupalLogin($this->drupalCreateUser(array('administer views', 'administer blocks')));
+
+    // Create a new view in the UI.
+    $edit = array();
+    $edit['label'] = $this->randomString();
+    $edit['id'] = strtolower($this->randomMachineName());
+    $edit['show[wizard_key]'] = 'standard:views_test_data';
+    $edit['description'] = $this->randomString();
+    $edit['block[create]'] = TRUE;
+    $edit['block[style][row_plugin]'] = 'fields';
+    $this->drupalPostForm('admin/structure/views/add', $edit, t('Save and edit'));
+
+    // Test that the block was given a default category corresponding to its
+    // base table.
+    $arguments = array(
+      ':id' => 'edit-category-lists-views',
+      ':li_class' => 'views-block' . Html::getClass($edit['id']) . '-block-1',
+      ':href' => \Drupal::Url('block.admin_add', array(
+        'plugin_id' => 'views_block:' . $edit['id'] . '-block_1',
+        'theme' => 'classy',
+      )),
+      ':text' => $edit['label'],
+    );
+    $this->drupalGet('admin/structure/block');
+    $elements = $this->xpath('//details[@id=:id]//li[contains(@class, :li_class)]/a[contains(@href, :href) and text()=:text]', $arguments);
+    $this->assertTrue(!empty($elements), 'The test block appears in the category for its base table.');
+
+    // Duplicate the block before changing the category.
+    $this->drupalPostForm('admin/structure/views/view/' . $edit['id'] . '/edit/block_1', array(), t('Duplicate @display_title', array('@display_title' => 'Block')));
+    $this->assertUrl('admin/structure/views/view/' . $edit['id'] . '/edit/block_2');
+
+    // Change the block category to a random string.
+    $this->drupalGet('admin/structure/views/view/' . $edit['id'] . '/edit/block_1');
+    $label = t('Lists (Views)');
+    $link = $this->xpath('//a[@id="views-block-1-block-category" and normalize-space(text())=:label]', array(':label' => $label));
+    $this->assertTrue(!empty($link));
+    $this->clickLink($label);
+    $category = $this->randomString();
+    $this->drupalPostForm(NULL, array('block_category' => $category), t('Apply'));
+
+    // Duplicate the block after changing the category.
+    $this->drupalPostForm(NULL, array(), t('Duplicate @display_title', array('@display_title' => 'Block')));
+    $this->assertUrl('admin/structure/views/view/' . $edit['id'] . '/edit/block_3');
+
+    $this->drupalPostForm(NULL, array(), t('Save'));
+
+    // Test that the blocks are listed under the correct categories.
+    $category_id = Html::getUniqueId('edit-category-' . SafeMarkup::checkPlain($category));
+    $arguments[':id'] = $category_id;
+    $this->drupalGet('admin/structure/block');
+    $elements = $this->xpath('//details[@id=:id]//li[contains(@class, :li_class)]/a[contains(@href, :href) and text()=:text]', $arguments);
+    $this->assertTrue(!empty($elements), 'The test block appears in the custom category.');
+
+    $arguments = array(
+      ':id' => 'edit-category-lists-views',
+      ':li_class' => 'views-block' . Html::getClass($edit['id']) . '-block-2',
+      ':href' => \Drupal::Url('block.admin_add', array(
+        'plugin_id' => 'views_block:' . $edit['id'] . '-block_2',
+        'theme' => 'classy',
+      )),
+      ':text' => $edit['label'],
+    );
+    $elements = $this->xpath('//details[@id=:id]//li[contains(@class, :li_class)]/a[contains(@href, :href) and text()=:text]', $arguments);
+    $this->assertTrue(!empty($elements), 'The first duplicated test block remains in the original category.');
+
+    $arguments = array(
+      ':id' => $category_id,
+      ':li_class' => 'views-block' . Html::getClass($edit['id']) . '-block-3',
+      ':href' => \Drupal::Url('block.admin_add', array(
+        'plugin_id' => 'views_block:' . $edit['id'] . '-block_3',
+        'theme' => 'classy',
+      )),
+      ':text' => $edit['label'],
+    );
+    $elements = $this->xpath('//details[@id=:id]//li[contains(@class, :li_class)]/a[contains(@href, :href) and text()=:text]', $arguments);
+    $this->assertTrue(!empty($elements), 'The second duplicated test block appears in the custom category.');
+  }
+
+  /**
+   * Tests removing a block display.
+   */
+  public function testDeleteBlockDisplay() {
+    // To test all combinations possible we first place create two instances
+    // of the block display of the first view.
+    $block_1 = $this->drupalPlaceBlock('views_block:test_view_block-block_1', array('label' => 'test_view_block-block_1:1'));
+    $block_2 = $this->drupalPlaceBlock('views_block:test_view_block-block_1', array('label' => 'test_view_block-block_1:2'));
+
+    // Then we add one instance of blocks for each of the two displays of the
+    // second view.
+    $block_3 = $this->drupalPlaceBlock('views_block:test_view_block2-block_1', array('label' => 'test_view_block2-block_1'));
+    $block_4 = $this->drupalPlaceBlock('views_block:test_view_block2-block_2', array('label' => 'test_view_block2-block_2'));
+
+    $this->drupalGet('test-page');
+    $this->assertBlockAppears($block_1);
+    $this->assertBlockAppears($block_2);
+    $this->assertBlockAppears($block_3);
+    $this->assertBlockAppears($block_4);
+
+    $block_storage = $this->container->get('entity.manager')->getStorage('block');
+
+    // Remove the block display, so both block entities from the first view
+    // should both disappear.
+    $view = Views::getView('test_view_block');
+    $view->initDisplay();
+    $view->displayHandlers->remove('block_1');
+    $view->storage->save();
+
+    $this->assertFalse($block_storage->load($block_1->id()), 'The block for this display was removed.');
+    $this->assertFalse($block_storage->load($block_2->id()), 'The block for this display was removed.');
+    $this->assertTrue($block_storage->load($block_3->id()), 'A block from another view was unaffected.');
+    $this->assertTrue($block_storage->load($block_4->id()), 'A block from another view was unaffected.');
+    $this->drupalGet('test-page');
+    $this->assertNoBlockAppears($block_1);
+    $this->assertNoBlockAppears($block_2);
+    $this->assertBlockAppears($block_3);
+    $this->assertBlockAppears($block_4);
+
+    // Remove the first block display of the second view and ensure the block
+    // instance of the second block display still exists.
+    $view = Views::getView('test_view_block2');
+    $view->initDisplay();
+    $view->displayHandlers->remove('block_1');
+    $view->storage->save();
+
+    $this->assertFalse($block_storage->load($block_3->id()), 'The block for this display was removed.');
+    $this->assertTrue($block_storage->load($block_4->id()), 'A block from another display on the same view was unaffected.');
+    $this->drupalGet('test-page');
+    $this->assertNoBlockAppears($block_3);
+    $this->assertBlockAppears($block_4);
+  }
+
+  /**
+   * Test the block form for a Views block.
+   */
+  public function testViewsBlockForm() {
+    $this->drupalLogin($this->drupalCreateUser(array('administer blocks')));
+    $default_theme = $this->config('system.theme')->get('default');
+    $this->drupalGet('admin/structure/block/add/views_block:test_view_block-block_1/' . $default_theme);
+    $elements = $this->xpath('//input[@name="label"]');
+    $this->assertTrue(empty($elements), 'The label field is not found for Views blocks.');
+    // Test that that machine name field is hidden from display and has been
+    // saved as expected from the default value.
+    $this->assertNoFieldById('edit-machine-name', 'views_block__test_view_block_1', 'The machine name is hidden on the views block form.');
+    // Save the block.
+    $this->drupalPostForm(NULL, array(), t('Save block'));
+    $storage = $this->container->get('entity.manager')->getStorage('block');
+    $block = $storage->load('views_block__test_view_block_block_1');
+    // This will only return a result if our new block has been created with the
+    // expected machine name.
+    $this->assertTrue(!empty($block), 'The expected block was loaded.');
+
+    for ($i = 2; $i <= 3; $i++) {
+      // Place the same block again and make sure we have a new ID.
+      $this->drupalPostForm('admin/structure/block/add/views_block:test_view_block-block_1/' . $default_theme, array(), t('Save block'));
+      $block = $storage->load('views_block__test_view_block_block_1_' . $i);
+      // This will only return a result if our new block has been created with the
+      // expected machine name.
+      $this->assertTrue(!empty($block), 'The expected block was loaded.');
+    }
+
+    // Tests the override capability of items per page.
+    $this->drupalGet('admin/structure/block/add/views_block:test_view_block-block_1/' . $default_theme);
+    $edit = array();
+    $edit['settings[override][items_per_page]'] = 10;
+
+    $this->drupalPostForm('admin/structure/block/add/views_block:test_view_block-block_1/' . $default_theme, $edit, t('Save block'));
+
+    $block = $storage->load('views_block__test_view_block_block_1_4');
+    $config = $block->getPlugin()->getConfiguration();
+    $this->assertEqual(10, $config['items_per_page'], "'Items per page' is properly saved.");
+
+    $edit['settings[override][items_per_page]'] = 5;
+    $this->drupalPostForm('admin/structure/block/manage/views_block__test_view_block_block_1_4', $edit, t('Save block'));
+
+    $block = $storage->load('views_block__test_view_block_block_1_4');
+
+    $config = $block->getPlugin()->getConfiguration();
+    $this->assertEqual(5, $config['items_per_page'], "'Items per page' is properly saved.");
+
+    // Tests the override of the label capability.
+    $edit = array();
+    $edit['settings[views_label_checkbox]'] = 1;
+    $edit['settings[views_label]'] = 'Custom title';
+    $this->drupalPostForm('admin/structure/block/add/views_block:test_view_block-block_1/' . $default_theme, $edit, t('Save block'));
+
+    $block = $storage->load('views_block__test_view_block_block_1_5');
+    $config = $block->getPlugin()->getConfiguration();
+    $this->assertEqual('Custom title', $config['views_label'], "'Label' is properly saved.");
+  }
+
+  /**
+   * Tests the actual rendering of the views block.
+   */
+  public function testBlockRendering() {
+    // Create a block and set a custom title.
+    $block = $this->drupalPlaceBlock('views_block:test_view_block-block_1', array('label' => 'test_view_block-block_1:1', 'views_label' => 'Custom title'));
+    $this->drupalGet('');
+
+    $result = $this->xpath('//div[contains(@class, "region-sidebar-first")]/div[contains(@class, "block-views")]/h2');
+    $this->assertEqual((string) $result[0], 'Custom title');
+
+    // Don't override the title anymore.
+    $plugin = $block->getPlugin();
+    $plugin->setConfigurationValue('views_label', '');
+    $block->save();
+
+    $this->drupalGet('');
+    $result = $this->xpath('//div[contains(@class, "region-sidebar-first")]/div[contains(@class, "block-views")]/h2');
+    $this->assertEqual((string) $result[0], 'test_view_block');
+
+    // Hide the title.
+    $block->getPlugin()->setConfigurationValue('label_display', FALSE);
+    $block->save();
+
+    $this->drupalGet('');
+    $result = $this->xpath('//div[contains(@class, "region-sidebar-first")]/div[contains(@class, "block-views")]/h2');
+    $this->assertTrue(empty($result), 'The title is not visible.');
+  }
+
+  /**
+   * Tests the contextual links on a Views block.
+   */
+  public function testBlockContextualLinks() {
+    $this->drupalLogin($this->drupalCreateUser(array('administer views', 'access contextual links', 'administer blocks')));
+    $block = $this->drupalPlaceBlock('views_block:test_view_block-block_1');
+    $cached_block = $this->drupalPlaceBlock('views_block:test_view_block-block_1');
+    $this->drupalGet('test-page');
+
+    $id = 'block:block=' . $block->id() . ':langcode=en|entity.view.edit_form:view=test_view_block:location=block&name=test_view_block&display_id=block_1&langcode=en';
+    $cached_id = 'block:block=' . $cached_block->id() . ':langcode=en|entity.view.edit_form:view=test_view_block:location=block&name=test_view_block&display_id=block_1&langcode=en';
+    // @see \Drupal\contextual\Tests\ContextualDynamicContextTest:assertContextualLinkPlaceHolder()
+    $this->assertRaw('<div' . new Attribute(array('data-contextual-id' => $id)) . '></div>', format_string('Contextual link placeholder with id @id exists.', array('@id' => $id)));
+    $this->assertRaw('<div' . new Attribute(array('data-contextual-id' => $cached_id)) . '></div>', format_string('Contextual link placeholder with id @id exists.', array('@id' => $cached_id)));
+
+    // Get server-rendered contextual links.
+    // @see \Drupal\contextual\Tests\ContextualDynamicContextTest:renderContextualLinks()
+    $post = array('ids[0]' => $id, 'ids[1]' => $cached_id);
+    $response = $this->drupalPostWithFormat('contextual/render', 'json', $post, array('query' => array('destination' => 'test-page')));
+    $this->assertResponse(200);
+    $json = Json::decode($response);
+    $this->assertIdentical($json[$id], '<ul class="contextual-links"><li class="block-configure"><a href="' . base_path() . 'admin/structure/block/manage/' . $block->id() . '">Configure block</a></li><li class="entityviewedit-form"><a href="' . base_path() . 'admin/structure/views/view/test_view_block/edit/block_1">Edit view</a></li></ul>');
+    $this->assertIdentical($json[$cached_id], '<ul class="contextual-links"><li class="block-configure"><a href="' . base_path() . 'admin/structure/block/manage/' . $cached_block->id() . '">Configure block</a></li><li class="entityviewedit-form"><a href="' . base_path() . 'admin/structure/views/view/test_view_block/edit/block_1">Edit view</a></li></ul>');
+  }
+
+}

core/modules/block/src/Theme/AdminDemoNegotiator.php

@@ -0,0 +1,34 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\Theme\AdminDemoNegotiator.
+ */
+
+namespace Drupal\block\Theme;
+
+use Drupal\Core\Routing\RouteMatchInterface;
+use Drupal\Core\Theme\ThemeNegotiatorInterface;
+
+/**
+ * Negotiates the theme for the block admin demo page via the URL.
+ */
+class AdminDemoNegotiator implements ThemeNegotiatorInterface {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function applies(RouteMatchInterface $route_match) {
+    return $route_match->getRouteName() == 'block.admin_demo';
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function determineActiveTheme(RouteMatchInterface $route_match) {
+    // We return exactly what was passed in, to guarantee that the page will
+    // always be displayed using the theme whose blocks are being configured.
+    return $route_match->getParameter('theme');
+  }
+
+}

core/modules/block/templates/block-list.html.twig

@@ -0,0 +1,23 @@
+{#
+/**
+ * @file
+ * Two column template for the block add/edit form.
+ *
+ * This template will be used when a block edit form specifies 'block_edit_form'
+ * as its #theme callback.  Otherwise, by default, block add/edit forms will be
+ * themed by form.html.twig.
+ *
+ * Available variables:
+ * - form: The block add/edit form.
+ *
+ * @ingroup themeable
+ */
+#}
+<div class="layout-block-list clearfix">
+  <div class="layout-region block-list-primary">
+    {{ form|without('place_blocks') }}
+  </div>
+  <div class="layout-region block-list-secondary">
+    {{ form.place_blocks }}
+  </div>
+</div>

core/modules/block/templates/block.html.twig

@@ -0,0 +1,46 @@
+{#
+/**
+ * @file
+ * Default theme implementation to display a block.
+ *
+ * Available variables:
+ * - plugin_id: The ID of the block implementation.
+ * - label: The configured label of the block if visible.
+ * - configuration: A list of the block's configuration values.
+ *   - label: The configured label for the block.
+ *   - label_display: The display settings for the label.
+ *   - module: The module that provided this block plugin.
+ *   - cache: The cache settings.
+ *   - Block plugin specific settings will also be stored here.
+ * - block - The full block entity.
+ *   - label_hidden: The hidden block title value if the block was
+ *     configured to hide the title ('label' is empty in this case).
+ *   - module: The module that generated the block.
+ *   - delta: An ID for the block, unique within each module.
+ *   - region: The block region embedding the current block.
+ * - content: The content of this block.
+ * - attributes: array of HTML attributes populated by modules, intended to
+ *   be added to the main container tag of this template.
+ *   - id: A valid HTML ID and guaranteed unique.
+ * - title_attributes: Same as attributes, except applied to the main title
+ *   tag that appears in the template.
+ * - title_prefix: Additional output populated by modules, intended to be
+ *   displayed in front of the main title tag that appears in the template.
+ * - title_suffix: Additional output populated by modules, intended to be
+ *   displayed after the main title tag that appears in the template.
+ *
+ * @see template_preprocess_block()
+ *
+ * @ingroup themeable
+ */
+#}
+<div{{ attributes }}>
+  {{ title_prefix }}
+  {% if label %}
+    <h2{{ title_attributes }}>{{ label }}</h2>
+  {% endif %}
+  {{ title_suffix }}
+  {% block content %}
+    {{ content }}
+  {% endblock %}
+</div>

core/modules/block/tests/modules/block_test/block_test.info.yml

@@ -0,0 +1,8 @@
+name: 'Block test'
+type: module
+description: 'Provides test blocks.'
+package: Testing
+version: VERSION
+core: 8.x
+dependencies:
+  - block

core/modules/block/tests/modules/block_test/block_test.module

@@ -0,0 +1,44 @@
+<?php
+
+/**
+ * @file
+ *   Provide test blocks.
+ */
+
+use Drupal\Core\Block\BlockPluginInterface;
+use Drupal\Core\Cache\Cache;
+
+/**
+ * Implements hook_block_alter().
+ */
+function block_test_block_alter(&$block_info) {
+  if (\Drupal::state()->get('block_test_info_alter') && isset($block_info['test_block_instantiation'])) {
+    $block_info['test_block_instantiation']['category'] = t('Custom category');
+  }
+}
+
+/**
+ * Implements hook_block_view_BASE_BLOCK_ID_alter().
+ */
+function block_test_block_view_test_cache_alter(array &$build, BlockPluginInterface $block) {
+  if (\Drupal::state()->get('block_test_view_alter_suffix') !== NULL) {
+    $build['#suffix'] = '<br>Goodbye!';
+  }
+  if (\Drupal::state()->get('block_test_view_alter_cache_key') !== NULL) {
+    $build['#cache']['keys'][] = \Drupal::state()->get('block_test_view_alter_cache_key');
+  }
+  if (\Drupal::state()->get('block_test_view_alter_cache_tag') !== NULL) {
+    $build['#cache']['tags'][] = \Drupal::state()->get('block_test_view_alter_cache_tag');
+  }
+  if (\Drupal::state()->get('block_test_view_alter_append_pre_render_prefix') !== NULL) {
+    $build['#pre_render'][] = 'block_test_pre_render_alter_content';
+  }
+}
+
+/**
+ * #pre_render callback for a block to alter its content.
+ */
+function block_test_pre_render_alter_content($build) {
+  $build['#prefix'] = 'Hiya!<br>';
+  return $build;
+}

core/modules/block/tests/modules/block_test/config/install/block.block.test_block.yml

@@ -0,0 +1,17 @@
+id: test_block
+theme: stark
+weight: 0
+status: true
+langcode: en
+region: '-1'
+plugin: test_html
+settings:
+  label: 'Test HTML block'
+  provider: block_test
+  label_display: 'hidden'
+dependencies:
+  module:
+    - block_test
+  theme:
+    - classy
+visibility: {  }

core/modules/block/tests/modules/block_test/config/schema/block_test.schema.yml

@@ -0,0 +1,7 @@
+block.settings.test_block_instantiation:
+  type: block_settings
+  label: 'Test block instantiation settings'
+  mapping:
+    display_message:
+      type: string
+      label: 'Message text'

core/modules/block/tests/modules/block_test/src/Plugin/Block/TestAccessBlock.php

@@ -0,0 +1,84 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block_test\Plugin\Block\TestAccessBlock.
+ */
+
+namespace Drupal\block_test\Plugin\Block;
+
+use Drupal\Core\Access\AccessResult;
+use Drupal\Core\Block\BlockBase;
+use Drupal\Core\Cache\Cache;
+use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
+use Drupal\Core\Session\AccountInterface;
+use Drupal\Core\State\StateInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * Provides a block to test access.
+ *
+ * @Block(
+ *   id = "test_access",
+ *   admin_label = @Translation("Test block access")
+ * )
+ */
+class TestAccessBlock extends BlockBase implements ContainerFactoryPluginInterface {
+
+  /**
+   * Tests the test access block.
+   *
+   *
+   * @param array $configuration
+   *   The plugin configuration, i.e. an array with configuration values keyed
+   *   by configuration option name. The special key 'context' may be used to
+   *   initialize the defined contexts by setting it to an array of context
+   *   values keyed by context names.
+   * @param string $plugin_id
+   *   The plugin_id for the plugin instance.
+   * @param mixed $plugin_definition
+   *   The plugin implementation definition.
+   * @param \Drupal\Core\State\StateInterface $state
+   *   The state.
+   */
+  public function __construct(array $configuration, $plugin_id, $plugin_definition, StateInterface $state) {
+    parent::__construct($configuration, $plugin_id, $plugin_definition);
+
+    $this->state = $state;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
+    return new static(
+      $configuration,
+      $plugin_id,
+      $plugin_definition,
+      $container->get('state')
+    );
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function blockAccess(AccountInterface $account) {
+    return $this->state->get('test_block_access', FALSE) ? AccessResult::allowed() : AccessResult::forbidden();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function build() {
+    return ['#markup' => 'Hello test world'];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getCacheMaxAge() {
+    return Cache::PERMANENT;
+  }
+
+}
+

core/modules/block/tests/modules/block_test/src/Plugin/Block/TestBlockInstantiation.php

@@ -0,0 +1,69 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block_test\Plugin\Block\TestBlockInstantiation.
+ */
+
+namespace Drupal\block_test\Plugin\Block;
+
+use Drupal\Core\Access\AccessResult;
+use Drupal\Core\Block\BlockBase;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Session\AccountInterface;
+
+/**
+ * Provides a basic block for testing block instantiation and configuration.
+ *
+ * @Block(
+ *   id = "test_block_instantiation",
+ *   admin_label = @Translation("Display message")
+ * )
+ */
+class TestBlockInstantiation extends BlockBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function defaultConfiguration() {
+    return array(
+      'display_message' => 'no message set',
+    );
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function blockAccess(AccountInterface $account) {
+    return AccessResult::allowedIfHasPermission($account, 'access content');
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function blockForm($form, FormStateInterface $form_state) {
+    $form['display_message'] = array(
+      '#type' => 'textfield',
+      '#title' => $this->t('Display message'),
+      '#default_value' => $this->configuration['display_message'],
+    );
+    return $form;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function blockSubmit($form, FormStateInterface $form_state) {
+    $this->configuration['display_message'] = $form_state->getValue('display_message');
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function build() {
+    return array(
+      '#children' => $this->configuration['display_message'],
+    );
+  }
+
+}

core/modules/block/tests/modules/block_test/src/Plugin/Block/TestCacheBlock.php

@@ -0,0 +1,42 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block_test\Plugin\Block\TestCacheBlock.
+ */
+
+namespace Drupal\block_test\Plugin\Block;
+
+use Drupal\Core\Block\BlockBase;
+
+/**
+ * Provides a block to test caching.
+ *
+ * @Block(
+ *   id = "test_cache",
+ *   admin_label = @Translation("Test block caching")
+ * )
+ */
+class TestCacheBlock extends BlockBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function build() {
+    $content = \Drupal::state()->get('block_test.content');
+
+    $build = array();
+    if (!empty($content)) {
+      $build['#markup'] = $content;
+    }
+    return $build;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getCacheContexts() {
+    return \Drupal::state()->get('block_test.cache_contexts', []);
+  }
+
+}

core/modules/block/tests/modules/block_test/src/Plugin/Block/TestContextAwareBlock.php

@@ -0,0 +1,36 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block_test\Plugin\Block\TestContextAwareBlock.
+ */
+
+namespace Drupal\block_test\Plugin\Block;
+
+use Drupal\Core\Block\BlockBase;
+
+/**
+ * Provides a context-aware block.
+ *
+ * @Block(
+ *   id = "test_context_aware",
+ *   admin_label = @Translation("Test context-aware block"),
+ *   context = {
+ *     "user" = @ContextDefinition("entity:user")
+ *   }
+ * )
+ */
+class TestContextAwareBlock extends BlockBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function build() {
+    /** @var $user \Drupal\user\UserInterface */
+    $user = $this->getContextValue('user');
+    return array(
+      '#markup' => $user->getUsername(),
+    );
+  }
+
+}

core/modules/block/tests/modules/block_test/src/Plugin/Block/TestHtmlBlock.php

@@ -0,0 +1,32 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block_test\Plugin\Block\TestHtmlBlock.
+ */
+
+namespace Drupal\block_test\Plugin\Block;
+
+use Drupal\Core\Block\BlockBase;
+
+/**
+ * Provides a block to test HTML.
+ *
+ * @Block(
+ *   id = "test_html",
+ *   admin_label = @Translation("Test HTML block")
+ * )
+ */
+class TestHtmlBlock extends BlockBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function build() {
+    return array(
+      '#attributes' => \Drupal::state()->get('block_test.attributes'),
+      '#children' => \Drupal::state()->get('block_test.content'),
+    );
+  }
+
+}

core/modules/block/tests/modules/block_test/src/Plugin/Block/TestXSSTitleBlock.php

@@ -0,0 +1,19 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block_test\Plugin\Block\TestXSSTitleBlock.
+ */
+
+namespace Drupal\block_test\Plugin\Block;
+
+/**
+ * Provides a block to test XSS in title.
+ *
+ * @Block(
+ *   id = "test_xss_title",
+ *   admin_label = "<script>alert('XSS subject');</script>"
+ * )
+ */
+class TestXSSTitleBlock extends TestCacheBlock {
+}

core/modules/block/tests/modules/block_test/themes/block_test_specialchars_theme/block_test_specialchars_theme.info.yml

@@ -0,0 +1,7 @@
+name: '<"Cat" & ''Mouse''>'
+type: theme
+description: 'Theme for testing special characters in block admin.'
+core: 8.x
+regions:
+  content: Content
+  help: Help

core/modules/block/tests/modules/block_test/themes/block_test_theme/block_test_theme.info.yml

@@ -0,0 +1,16 @@
+name: 'Block test theme'
+type: theme
+description: 'Theme for testing the block system'
+version: VERSION
+core: 8.x
+regions:
+  sidebar_first: 'Left sidebar'
+  sidebar_second: 'Right sidebar'
+  content: Content
+  header: Header
+  footer: Footer
+  highlighted: Highlighted
+  help: Help
+regions_hidden:
+  - sidebar_first
+  - sidebar_second

core/modules/block/tests/modules/block_test_views/block_test_views.info.yml

@@ -0,0 +1,9 @@
+name: 'Block test views'
+type: module
+description: 'Provides a view and block to test block displays in views.'
+package: Testing
+version: VERSION
+core: 8.x
+dependencies:
+  - block
+  - views

core/modules/block/tests/modules/block_test_views/test_views/views.view.test_view_block.yml

@@ -0,0 +1,45 @@
+langcode: en
+status: true
+dependencies: {  }
+id: test_view_block
+label: test_view_block
+module: views
+description: ''
+tag: ''
+base_table: views_test_data
+base_field: id
+core: 8.x
+display:
+  default:
+    display_plugin: default
+    id: default
+    display_title: Master
+    position: null
+    display_options:
+      access:
+        type: none
+      cache:
+        type: tag
+      query:
+        type: views_query
+      exposed_form:
+        type: basic
+      pager:
+        type: some
+        options:
+          items_per_page: 5
+      style:
+        type: default
+      row:
+        type: fields
+      fields:
+        name:
+          id: name
+          table: views_test_data
+          field: name
+      title: test_view_block
+  block_1:
+    display_plugin: block
+    id: block_1
+    display_title: Block
+    position: null

core/modules/block/tests/modules/block_test_views/test_views/views.view.test_view_block2.yml

@@ -0,0 +1,57 @@
+langcode: en
+status: true
+dependencies:
+  module:
+    - user
+id: test_view_block2
+label: test_view_block2
+module: views
+description: ''
+tag: ''
+base_table: views_test_data
+base_field: id
+core: 8.x
+display:
+  default:
+    display_plugin: default
+    id: default
+    display_title: Master
+    position: null
+    display_options:
+      access:
+        type: perm
+      cache:
+        type: tag
+      query:
+        type: views_query
+      exposed_form:
+        type: basic
+      pager:
+        type: some
+        options:
+          items_per_page: 5
+      style:
+        type: default
+      row:
+        type: fields
+      fields:
+        name:
+          id: name
+          table: views_test_data
+          field: name
+      title: test_view_block2
+  block_1:
+    display_plugin: block
+    id: block_1
+    display_title: Block
+    position: null
+  block_2:
+    display_plugin: block
+    id: block_2
+    display_title: Block
+    position: null
+  block_3:
+    display_plugin: block
+    id: block_3
+    display_title: Block
+    position: null

core/modules/block/tests/src/Unit/BlockConfigEntityUnitTest.php

@@ -0,0 +1,108 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Tests\block\Unit\BlockConfigEntityUnitTest.
+ */
+
+namespace Drupal\Tests\block\Unit;
+
+use Drupal\Core\DependencyInjection\ContainerBuilder;
+use Drupal\Tests\Core\Plugin\Fixtures\TestConfigurablePlugin;
+use Drupal\Tests\UnitTestCase;
+
+/**
+ * @coversDefaultClass \Drupal\block\Entity\Block
+ * @group block
+ */
+class BlockConfigEntityUnitTest extends UnitTestCase {
+
+  /**
+   * The entity type used for testing.
+   *
+   * @var \Drupal\Core\Entity\EntityTypeInterface|\PHPUnit_Framework_MockObject_MockObject
+   */
+  protected $entityType;
+
+  /**
+   * The entity manager used for testing.
+   *
+   * @var \Drupal\Core\Entity\EntityManagerInterface|\PHPUnit_Framework_MockObject_MockObject
+   */
+  protected $entityManager;
+
+  /**
+   * The ID of the type of the entity under test.
+   *
+   * @var string
+   */
+  protected $entityTypeId;
+
+  /**
+   * The UUID generator used for testing.
+   *
+   * @var \Drupal\Component\Uuid\UuidInterface|\PHPUnit_Framework_MockObject_MockObject
+   */
+  protected $uuid;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    $this->entityTypeId = $this->randomMachineName();
+
+    $this->entityType = $this->getMock('\Drupal\Core\Entity\EntityTypeInterface');
+    $this->entityType->expects($this->any())
+      ->method('getProvider')
+      ->will($this->returnValue('block'));
+
+    $this->entityManager = $this->getMock('\Drupal\Core\Entity\EntityManagerInterface');
+    $this->entityManager->expects($this->any())
+      ->method('getDefinition')
+      ->with($this->entityTypeId)
+      ->will($this->returnValue($this->entityType));
+
+    $this->uuid = $this->getMock('\Drupal\Component\Uuid\UuidInterface');
+
+    $container = new ContainerBuilder();
+    $container->set('entity.manager', $this->entityManager);
+    $container->set('uuid', $this->uuid);
+    \Drupal::setContainer($container);
+  }
+
+  /**
+   * @covers ::calculateDependencies
+   */
+  public function testCalculateDependencies() {
+    $values = array('theme' => 'stark');
+    // Mock the entity under test so that we can mock getPluginCollections().
+    $entity = $this->getMockBuilder('\Drupal\block\Entity\Block')
+      ->setConstructorArgs(array($values, $this->entityTypeId))
+      ->setMethods(array('getPluginCollections'))
+      ->getMock();
+    // Create a configurable plugin that would add a dependency.
+    $instance_id = $this->randomMachineName();
+    $instance = new TestConfigurablePlugin(array(), $instance_id, array('provider' => 'test'));
+
+    // Create a plugin collection to contain the instance.
+    $plugin_collection = $this->getMockBuilder('\Drupal\Core\Plugin\DefaultLazyPluginCollection')
+      ->disableOriginalConstructor()
+      ->setMethods(array('get'))
+      ->getMock();
+    $plugin_collection->expects($this->atLeastOnce())
+      ->method('get')
+      ->with($instance_id)
+      ->will($this->returnValue($instance));
+    $plugin_collection->addInstanceId($instance_id);
+
+    // Return the mocked plugin collection.
+    $entity->expects($this->once())
+      ->method('getPluginCollections')
+      ->will($this->returnValue(array($plugin_collection)));
+
+    $dependencies = $entity->calculateDependencies();
+    $this->assertContains('test', $dependencies['module']);
+    $this->assertContains('stark', $dependencies['theme']);
+  }
+
+}

core/modules/block/tests/src/Unit/BlockFormTest.php

@@ -0,0 +1,125 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Tests\block\Unit\BlockFormTest.
+ */
+
+namespace Drupal\Tests\block\Unit;
+
+use Drupal\block\BlockForm;
+use Drupal\Tests\UnitTestCase;
+
+/**
+ * @coversDefaultClass \Drupal\block\BlockForm
+ * @group block
+ */
+class BlockFormTest extends UnitTestCase {
+
+  /**
+   * The condition plugin manager.
+   *
+   * @var \Drupal\Core\Executable\ExecutableManagerInterface|\PHPUnit_Framework_MockObject_MockObject
+   */
+  protected $conditionManager;
+
+  /**
+   * The block storage.
+   *
+   * @var \Drupal\Core\Entity\EntityStorageInterface|\PHPUnit_Framework_MockObject_MockObject
+   */
+  protected $storage;
+
+  /**
+   * The event dispatcher service.
+   *
+   * @var \Symfony\Component\EventDispatcher\EventDispatcherInterface|\PHPUnit_Framework_MockObject_MockObject
+   */
+  protected $dispatcher;
+
+  /**
+   * The language manager service.
+   *
+   * @var \Drupal\Core\Language\LanguageManagerInterface|\PHPUnit_Framework_MockObject_MockObject
+   */
+  protected $language;
+
+
+  /**
+   * The theme handler.
+   *
+   * @var \Drupal\Core\Extension\ThemeHandlerInterface|\PHPUnit_Framework_MockObject_MockObject
+   */
+  protected $themeHandler;
+
+  /**
+   * The entity manager.
+   *
+   * @var \Drupal\Core\Entity\EntityManagerInterface|\PHPUnit_Framework_MockObject_MockObject
+   */
+  protected $entityManager;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+
+    $this->conditionManager = $this->getMock('Drupal\Core\Executable\ExecutableManagerInterface');
+    $this->language = $this->getMock('Drupal\Core\Language\LanguageManagerInterface');
+    $this->dispatcher = $this->getMock('Symfony\Component\EventDispatcher\EventDispatcherInterface');
+
+    $this->entityManager = $this->getMock('Drupal\Core\Entity\EntityManagerInterface');
+    $this->storage = $this->getMock('Drupal\Core\Config\Entity\ConfigEntityStorageInterface');
+    $this->themeHandler = $this->getMock('Drupal\Core\Extension\ThemeHandlerInterface');
+    $this->entityManager->expects($this->any())
+      ->method('getStorage')
+      ->will($this->returnValue($this->storage));
+
+  }
+
+  /**
+   * Tests the unique machine name generator.
+   *
+   * @see \Drupal\block\BlockForm::getUniqueMachineName()
+   */
+  public function testGetUniqueMachineName() {
+    $blocks = array();
+
+    $blocks['test'] = $this->getBlockMockWithMachineName('test');
+    $blocks['other_test'] = $this->getBlockMockWithMachineName('other_test');
+    $blocks['other_test_1'] = $this->getBlockMockWithMachineName('other_test');
+    $blocks['other_test_2'] = $this->getBlockMockWithMachineName('other_test');
+
+    $query = $this->getMock('Drupal\Core\Entity\Query\QueryInterface');
+    $query->expects($this->exactly(5))
+      ->method('condition')
+      ->will($this->returnValue($query));
+
+    $query->expects($this->exactly(5))
+      ->method('execute')
+      ->will($this->returnValue(array('test', 'other_test', 'other_test_1', 'other_test_2')));
+
+    $this->storage->expects($this->exactly(5))
+      ->method('getQuery')
+      ->will($this->returnValue($query));
+
+    $block_form_controller = new BlockForm($this->entityManager, $this->conditionManager, $this->dispatcher, $this->language, $this->themeHandler);
+
+    // Ensure that the block with just one other instance gets the next available
+    // name suggestion.
+    $this->assertEquals('test_2', $block_form_controller->getUniqueMachineName($blocks['test']));
+
+    // Ensure that the block with already three instances (_0, _1, _2) gets the
+    // 4th available name.
+    $this->assertEquals('other_test_3', $block_form_controller->getUniqueMachineName($blocks['other_test']));
+    $this->assertEquals('other_test_3', $block_form_controller->getUniqueMachineName($blocks['other_test_1']));
+    $this->assertEquals('other_test_3', $block_form_controller->getUniqueMachineName($blocks['other_test_2']));
+
+    // Ensure that a block without an instance yet gets the suggestion as
+    // unique machine name.
+    $last_block = $this->getBlockMockWithMachineName('last_test');
+    $this->assertEquals('last_test', $block_form_controller->getUniqueMachineName($last_block));
+  }
+
+}

core/modules/block/tests/src/Unit/BlockRepositoryTest.php

@@ -0,0 +1,185 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Tests\block\Unit\BlockRepositoryTest.
+ */
+
+namespace Drupal\Tests\block\Unit;
+
+use Drupal\block\BlockRepository;
+use Drupal\Core\Block\BlockPluginInterface;
+use Drupal\Core\Plugin\ContextAwarePluginInterface;
+use Drupal\Tests\UnitTestCase;
+
+/**
+ * @coversDefaultClass \Drupal\block\BlockRepository
+ * @group block
+ */
+class BlockRepositoryTest extends UnitTestCase {
+
+  /**
+   * @var \Drupal\block\BlockRepository
+   */
+  protected $blockRepository;
+
+  /**
+   * @var \Drupal\Core\Entity\EntityStorageInterface|\PHPUnit_Framework_MockObject_MockObject
+   */
+  protected $blockStorage;
+
+  /**
+   * @var string
+   */
+  protected $theme;
+
+  /**
+   * @var \Drupal\Core\Plugin\Context\ContextHandlerInterface|\PHPUnit_Framework_MockObject_MockObject
+   */
+  protected $contextHandler;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+    $active_theme = $this->getMockBuilder('Drupal\Core\Theme\ActiveTheme')
+      ->disableOriginalConstructor()
+      ->getMock();
+    $this->theme = $this->randomMachineName();
+    $active_theme->expects($this->atLeastOnce())
+      ->method('getName')
+      ->willReturn($this->theme);
+    $active_theme->expects($this->atLeastOnce())
+      ->method('getRegions')
+      ->willReturn([
+        'top',
+        'center',
+        'bottom',
+      ]);
+
+    $theme_manager = $this->getMock('Drupal\Core\Theme\ThemeManagerInterface');
+    $theme_manager->expects($this->once())
+      ->method('getActiveTheme')
+      ->will($this->returnValue($active_theme));
+
+    $this->contextHandler = $this->getMock('Drupal\Core\Plugin\Context\ContextHandlerInterface');
+    $this->blockStorage = $this->getMock('Drupal\Core\Entity\EntityStorageInterface');
+    $entity_manager = $this->getMock('Drupal\Core\Entity\EntityManagerInterface');
+    $entity_manager->expects($this->any())
+      ->method('getStorage')
+      ->willReturn($this->blockStorage);
+
+    $this->blockRepository = new BlockRepository($entity_manager, $theme_manager, $this->contextHandler);
+  }
+
+  /**
+   * Tests the retrieval of block entities.
+   *
+   * @covers ::getVisibleBlocksPerRegion
+   *
+   * @dataProvider providerBlocksConfig
+   */
+  public function testGetVisibleBlocksPerRegion(array $blocks_config, array $expected_blocks) {
+    $blocks = [];
+    foreach ($blocks_config as $block_id => $block_config) {
+      $block = $this->getMock('Drupal\block\BlockInterface');
+      $block->expects($this->once())
+        ->method('setContexts')
+        ->willReturnSelf();
+      $block->expects($this->once())
+        ->method('access')
+        ->will($this->returnValue($block_config[0]));
+      $block->expects($block_config[0] ? $this->atLeastOnce() : $this->never())
+        ->method('getRegion')
+        ->willReturn($block_config[1]);
+      $blocks[$block_id] = $block;
+    }
+
+    $this->blockStorage->expects($this->once())
+      ->method('loadByProperties')
+      ->with(['theme' => $this->theme])
+      ->willReturn($blocks);
+    $result = [];
+    foreach ($this->blockRepository->getVisibleBlocksPerRegion([]) as $region => $resulting_blocks) {
+      $result[$region] = [];
+      foreach ($resulting_blocks as $plugin_id => $block) {
+        $result[$region][] = $plugin_id;
+      }
+    }
+    $this->assertSame($result, $expected_blocks);
+  }
+
+  public function providerBlocksConfig() {
+    $blocks_config = array(
+      'block1' => array(
+        TRUE, 'top', 0
+      ),
+      // Test a block without access.
+      'block2' => array(
+        FALSE, 'bottom', 0
+      ),
+      // Test two blocks in the same region with specific weight.
+      'block3' => array(
+        TRUE, 'bottom', 5
+      ),
+      'block4' => array(
+        TRUE, 'bottom', -5
+      ),
+    );
+
+    $test_cases = [];
+    $test_cases[] = [$blocks_config,
+      [
+        'top' => ['block1'],
+        'center' => [],
+        'bottom' => ['block4', 'block3'],
+      ]
+    ];
+    return $test_cases;
+  }
+
+  /**
+   * Tests the retrieval of block entities that are context-aware.
+   *
+   * @covers ::getVisibleBlocksPerRegion
+   */
+  public function testGetVisibleBlocksPerRegionWithContext() {
+    $block = $this->getMock('Drupal\block\BlockInterface');
+    $block->expects($this->once())
+      ->method('setContexts')
+      ->willReturnSelf();
+    $block->expects($this->once())
+      ->method('access')
+      ->willReturn(TRUE);
+    $block->expects($this->once())
+      ->method('getRegion')
+      ->willReturn('top');
+    $blocks['block_id'] = $block;
+
+    $contexts = [];
+    $this->blockStorage->expects($this->once())
+      ->method('loadByProperties')
+      ->with(['theme' => $this->theme])
+      ->willReturn($blocks);
+    $result = [];
+    foreach ($this->blockRepository->getVisibleBlocksPerRegion($contexts) as $region => $resulting_blocks) {
+      $result[$region] = [];
+      foreach ($resulting_blocks as $plugin_id => $block) {
+        $result[$region][] = $plugin_id;
+      }
+    }
+    $expected = [
+      'top' => [
+        'block_id',
+      ],
+      'center' => [],
+      'bottom' => [],
+    ];
+    $this->assertSame($expected, $result);
+  }
+
+}
+
+interface TestContextAwareBlockInterface extends BlockPluginInterface, ContextAwarePluginInterface {
+}

core/modules/block/tests/src/Unit/CategoryAutocompleteTest.php

@@ -0,0 +1,90 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Tests\block\Unit\CategoryAutocompleteTest.
+ */
+
+namespace Drupal\Tests\block\Unit;
+
+use Drupal\block\Controller\CategoryAutocompleteController;
+use Drupal\Component\Utility\SafeMarkup;
+use Drupal\Tests\UnitTestCase;
+use Symfony\Component\HttpFoundation\Request;
+
+/**
+ * @coversDefaultClass \Drupal\block\Controller\CategoryAutocompleteController
+ * @group block
+ */
+class CategoryAutocompleteTest extends UnitTestCase {
+
+  /**
+   * The autocomplete controller.
+   *
+   * @var \Drupal\block\Controller\CategoryAutocompleteController
+   */
+  protected $autocompleteController;
+
+  protected function setUp() {
+    $block_manager = $this->getMock('Drupal\Core\Block\BlockManagerInterface');
+    $block_manager->expects($this->any())
+      ->method('getCategories')
+      ->will($this->returnValue(array('Comment', 'Node', 'None & Such', 'User')));
+
+    $this->autocompleteController = new CategoryAutocompleteController($block_manager);
+  }
+
+  /**
+   * Tests the autocomplete method.
+   *
+   * @param string $string
+   *   The string entered into the autocomplete.
+   * @param array $suggestions
+   *   The array of expected suggestions.
+   *
+   * @see \Drupal\block\Controller\CategoryAutocompleteController::autocomplete()
+   *
+   * @dataProvider providerTestAutocompleteSuggestions
+   */
+  public function testAutocompleteSuggestions($string, $suggestions) {
+    $suggestions = array_map(function ($suggestion) {
+      return array('value' => $suggestion, 'label' => SafeMarkup::checkPlain($suggestion));
+    }, $suggestions);
+    $result = $this->autocompleteController->autocomplete(new Request(array('q' => $string)));
+    $this->assertSame($suggestions, json_decode($result->getContent(), TRUE));
+  }
+
+  /**
+   * Data provider for testAutocompleteSuggestions().
+   *
+   * @return array
+   */
+  public function providerTestAutocompleteSuggestions() {
+    $test_parameters = array();
+    $test_parameters[] = array(
+      'string' => 'Com',
+      'suggestions' => array(
+        'Comment',
+      ),
+    );
+    $test_parameters[] = array(
+      'string' => 'No',
+      'suggestions' => array(
+        'Node',
+        'None & Such',
+      ),
+    );
+    $test_parameters[] = array(
+      'string' => 'us',
+      'suggestions' => array(
+        'User',
+      ),
+    );
+    $test_parameters[] = array(
+      'string' => 'Banana',
+      'suggestions' => array(),
+    );
+    return $test_parameters;
+  }
+
+}

core/modules/block/tests/src/Unit/Menu/BlockLocalTasksTest.php

@@ -0,0 +1,82 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Tests\block\Unit\Menu\BlockLocalTasksTest.
+ */
+
+namespace Drupal\Tests\block\Unit\Menu;
+
+use Drupal\Tests\Core\Menu\LocalTaskIntegrationTestBase;
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+
+/**
+ * Tests block local tasks.
+ *
+ * @group block
+ */
+class BlockLocalTasksTest extends LocalTaskIntegrationTestBase {
+
+  protected function setUp() {
+    $this->directoryList = array('block' => 'core/modules/block');
+    parent::setUp();
+
+    $config_factory = $this->getConfigFactoryStub(array('system.theme' => array(
+      'default' => 'test_c',
+    )));
+
+    $themes = array();
+    $themes['test_a'] = (object) array(
+      'status' => 0,
+    );
+    $themes['test_b'] = (object) array(
+      'status' => 1,
+      'info' => array(
+        'name' => 'test_b',
+      ),
+    );
+    $themes['test_c'] = (object) array(
+      'status' => 1,
+      'info' => array(
+        'name' => 'test_c',
+      ),
+    );
+    $theme_handler = $this->getMock('Drupal\Core\Extension\ThemeHandlerInterface');
+    $theme_handler->expects($this->any())
+      ->method('listInfo')
+      ->will($this->returnValue($themes));
+
+    $container = new ContainerBuilder();
+    $container->set('config.factory', $config_factory);
+    $container->set('theme_handler', $theme_handler);
+    $container->set('app.root', $this->root);
+    \Drupal::setContainer($container);
+  }
+
+  /**
+   * Tests the admin edit local task.
+   */
+  public function testBlockAdminLocalTasks() {
+    $this->assertLocalTasks('entity.block.edit_form', array(array('entity.block.edit_form')));
+  }
+
+  /**
+   * Tests the block admin display local tasks.
+   *
+   * @dataProvider providerTestBlockAdminDisplay
+   */
+  public function testBlockAdminDisplay($route, $expected) {
+    $this->assertLocalTasks($route, $expected);
+  }
+
+  /**
+   * Provides a list of routes to test.
+   */
+  public function providerTestBlockAdminDisplay() {
+    return array(
+      array('block.admin_display', array(array('block.admin_display'), array('block.admin_display_theme:test_b', 'block.admin_display_theme:test_c'))),
+      array('block.admin_display_theme', array(array('block.admin_display'), array('block.admin_display_theme:test_b', 'block.admin_display_theme:test_c'))),
+    );
+  }
+
+}

core/modules/block/tests/src/Unit/Plugin/DisplayVariant/BlockPageVariantTest.php

@@ -0,0 +1,241 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Tests\block\Unit\Plugin\DisplayVariant\BlockPageVariantTest.
+ */
+
+namespace Drupal\Tests\block\Unit\Plugin\DisplayVariant;
+
+use Drupal\Tests\UnitTestCase;
+
+/**
+ * @coversDefaultClass \Drupal\block\Plugin\DisplayVariant\BlockPageVariant
+ * @group block
+ */
+class BlockPageVariantTest extends UnitTestCase {
+
+  /**
+   * The block repository.
+   *
+   * @var \Drupal\block\BlockRepositoryInterface|\PHPUnit_Framework_MockObject_MockObject
+   */
+  protected $blockRepository;
+
+  /**
+   * The block view builder.
+   *
+   * @var \Drupal\Core\Entity\EntityViewBuilderInterface|\PHPUnit_Framework_MockObject_MockObject
+   */
+  protected $blockViewBuilder;
+
+  /**
+   * The event dispatcher.
+   *
+   * @var \Symfony\Component\EventDispatcher\EventDispatcherInterface|\PHPUnit_Framework_MockObject_MockObject
+   */
+  protected $dispatcher;
+
+  /**
+   * The plugin context handler.
+   *
+   * @var \Drupal\Core\Plugin\Context\ContextHandlerInterface|\PHPUnit_Framework_MockObject_MockObject
+   */
+  protected $contextHandler;
+
+  /**
+   * Sets up a display variant plugin for testing.
+   *
+   * @param array $configuration
+   *   An array of plugin configuration.
+   * @param array $definition
+   *   The plugin definition array.
+   *
+   * @return \Drupal\block\Plugin\DisplayVariant\BlockPageVariant|\PHPUnit_Framework_MockObject_MockObject
+   *   A mocked display variant plugin.
+   */
+  public function setUpDisplayVariant($configuration = array(), $definition = array()) {
+    $this->blockRepository = $this->getMock('Drupal\block\BlockRepositoryInterface');
+    $this->blockViewBuilder = $this->getMock('Drupal\Core\Entity\EntityViewBuilderInterface');
+    $this->dispatcher = $this->getMock('Symfony\Component\EventDispatcher\EventDispatcherInterface');
+    $this->dispatcher->expects($this->any())
+      ->method('dispatch')
+      ->willReturnArgument(1);
+    return $this->getMockBuilder('Drupal\block\Plugin\DisplayVariant\BlockPageVariant')
+      ->setConstructorArgs(array($configuration, 'test', $definition, $this->blockRepository, $this->blockViewBuilder, $this->dispatcher, ['config:block_list']))
+      ->setMethods(array('getRegionNames'))
+      ->getMock();
+  }
+
+  public function providerBuild() {
+    $blocks_config = array(
+      'block1' => array(
+        // region, is main content block, is messages block
+        'top', FALSE, FALSE,
+      ),
+      // Test multiple blocks in the same region.
+      'block2' => array(
+        'bottom', FALSE, FALSE,
+      ),
+      'block3' => array(
+        'bottom', FALSE, FALSE,
+      ),
+      // Test a block implementing MainContentBlockPluginInterface.
+      'block4' => array(
+        'center', TRUE, FALSE,
+      ),
+      // Test a block implementing MessagesBlockPluginInterface.
+      'block5' => array(
+        'center', FALSE, TRUE,
+      ),
+    );
+
+    $test_cases = [];
+    $test_cases[] = [$blocks_config, 5,
+      [
+        '#cache' => [
+          'tags' => [
+            'config:block_list',
+          ],
+        ],
+        'top' => [
+          'block1' => [],
+          '#sorted' => TRUE,
+        ],
+        // The main content was rendered via a block.
+        'center' => [
+          'block4' => [],
+          'block5' => [],
+          '#sorted' => TRUE,
+        ],
+        'bottom' => [
+          'block2' => [],
+          'block3' => [],
+          '#sorted' => TRUE,
+        ],
+      ],
+    ];
+    unset($blocks_config['block5']);
+    $test_cases[] = [$blocks_config, 4,
+      [
+        '#cache' => [
+          'tags' => [
+            'config:block_list',
+          ],
+        ],
+        'top' => [
+          'block1' => [],
+          '#sorted' => TRUE,
+        ],
+        'center' => [
+          'block4' => [],
+          '#sorted' => TRUE,
+        ],
+        'bottom' => [
+          'block2' => [],
+          'block3' => [],
+          '#sorted' => TRUE,
+        ],
+        // The messages are rendered via the fallback in case there is no block
+        // rendering the main content.
+        'content' => [
+          'messages' => [
+            '#weight' => -1000,
+            '#type' => 'status_messages',
+          ],
+        ],
+      ],
+    ];
+    unset($blocks_config['block4']);
+    $test_cases[] = [$blocks_config, 3,
+      [
+        '#cache' => [
+          'tags' => [
+            'config:block_list',
+          ],
+        ],
+        'top' => [
+          'block1' => [],
+          '#sorted' => TRUE,
+        ],
+        'bottom' => [
+          'block2' => [],
+          'block3' => [],
+          '#sorted' => TRUE,
+        ],
+        // The main content & messages are rendered via the fallback in case
+        // there are no blocks rendering them.
+        'content' => [
+          'system_main' => ['#markup' => 'Hello kittens!'],
+          'messages' => [
+            '#weight' => -1000,
+            '#type' => 'status_messages',
+          ],
+        ],
+      ],
+    ];
+    return $test_cases;
+  }
+
+  /**
+   * Tests the building of a full page variant.
+   *
+   * @covers ::build
+   *
+   * @dataProvider providerBuild
+   */
+  public function testBuild(array $blocks_config, $visible_block_count, array $expected_render_array) {
+    $display_variant = $this->setUpDisplayVariant();
+    $display_variant->setMainContent(['#markup' => 'Hello kittens!']);
+
+    $blocks = ['top' => [], 'center' => [], 'bottom' => []];
+    $block_plugin = $this->getMock('Drupal\Core\Block\BlockPluginInterface');
+    $main_content_block_plugin = $this->getMock('Drupal\Core\Block\MainContentBlockPluginInterface');
+    $messages_block_plugin = $this->getMock('Drupal\Core\Block\MessagesBlockPluginInterface');
+    foreach ($blocks_config as $block_id => $block_config) {
+      $block = $this->getMock('Drupal\block\BlockInterface');
+      $block->expects($this->atLeastOnce())
+        ->method('getPlugin')
+        ->willReturn($block_config[1] ? $main_content_block_plugin : ($block_config[2] ? $messages_block_plugin : $block_plugin));
+      $blocks[$block_config[0]][$block_id] = $block;
+    }
+
+    $this->blockViewBuilder->expects($this->exactly($visible_block_count))
+      ->method('view')
+      ->will($this->returnValue(array()));
+    $this->blockRepository->expects($this->once())
+      ->method('getVisibleBlocksPerRegion')
+      ->will($this->returnValue($blocks));
+
+    $this->assertSame($expected_render_array, $display_variant->build());
+  }
+
+  /**
+   * Tests the building of a full page variant with no main content set.
+   *
+   * @covers ::build
+   */
+  public function testBuildWithoutMainContent() {
+    $display_variant = $this->setUpDisplayVariant();
+    $this->blockRepository->expects($this->once())
+      ->method('getVisibleBlocksPerRegion')
+      ->willReturn([]);
+
+    $expected = [
+      '#cache' => [
+        'tags' => [
+          'config:block_list',
+        ],
+      ],
+      'content' => [
+        'system_main' => [],
+        'messages' => [
+          '#weight' => -1000,
+          '#type' => 'status_messages',
+        ],
+      ],
+    ];
+    $this->assertSame($expected, $display_variant->build());
+  }
+
+}