Update to Drupal 8.2.6. For more information, see https://www.drupal.org/project/drupal/releases/8.2.6

vendor/symfony/http-foundation/File/File.php

@@ -68,7 +68,7 @@ class File extends \SplFileInfo
      * mime_content_type() and the system binary "file" (in this order), depending on
      * which of those are available.
      *
-     * @return string|null The guessed mime type (i.e. "application/pdf")
+     * @return string|null The guessed mime type (e.g. "application/pdf")
      *
      * @see MimeTypeGuesser
      */
@@ -85,7 +85,7 @@ class File extends \SplFileInfo
      * @param string $directory The destination folder
      * @param string $name      The new file name
      *
-     * @return File A File object representing the new file
+     * @return self A File object representing the new file
      *
      * @throws FileException if the target file could not be created
      */

vendor/symfony/http-foundation/File/MimeType/ExtensionGuesser.php

@@ -42,7 +42,7 @@ class ExtensionGuesser implements ExtensionGuesserInterface
     /**
      * Returns the singleton instance.
      *
-     * @return ExtensionGuesser
+     * @return self
      */
     public static function getInstance()
     {

vendor/symfony/http-foundation/File/MimeType/FileinfoMimeTypeGuesser.php

@@ -28,7 +28,7 @@ class FileinfoMimeTypeGuesser implements MimeTypeGuesserInterface
      *
      * @param string $magicFile A magic file to use with the finfo instance
      *
-     * @link http://www.php.net/manual/en/function.finfo-open.php
+     * @see http://www.php.net/manual/en/function.finfo-open.php
      */
     public function __construct($magicFile = null)
     {

vendor/symfony/http-foundation/File/MimeType/MimeTypeExtensionGuesser.php

@@ -661,6 +661,7 @@ class MimeTypeExtensionGuesser implements ExtensionGuesserInterface
         'image/gif' => 'gif',
         'image/ief' => 'ief',
         'image/jpeg' => 'jpeg',
+        'image/pjpeg' => 'jpeg',
         'image/ktx' => 'ktx',
         'image/png' => 'png',
         'image/prs.btif' => 'btif',

vendor/symfony/http-foundation/File/MimeType/MimeTypeGuesser.php

@@ -56,7 +56,7 @@ class MimeTypeGuesser implements MimeTypeGuesserInterface
     /**
      * Returns the singleton instance.
      *
-     * @return MimeTypeGuesser
+     * @return self
      */
     public static function getInstance()
     {

vendor/symfony/http-foundation/File/UploadedFile.php

@@ -50,7 +50,7 @@ class UploadedFile extends File
     /**
      * The file size provided by the uploader.
      *
-     * @var string
+     * @var int|null
      */
     private $size;
 
@@ -75,12 +75,12 @@ class UploadedFile extends File
      *
      * Calling any other method on an non-valid instance will cause an unpredictable result.
      *
-     * @param string $path         The full temporary path to the file
-     * @param string $originalName The original file name
-     * @param string $mimeType     The type of the file as provided by PHP
-     * @param int    $size         The file size
-     * @param int    $error        The error constant of the upload (one of PHP's UPLOAD_ERR_XXX constants)
-     * @param bool   $test         Whether the test mode is active
+     * @param string      $path         The full temporary path to the file
+     * @param string      $originalName The original file name
+     * @param string|null $mimeType     The type of the file as provided by PHP; null defaults to application/octet-stream
+     * @param int|null    $size         The file size
+     * @param int|null    $error        The error constant of the upload (one of PHP's UPLOAD_ERR_XXX constants); null defaults to UPLOAD_ERR_OK
+     * @param bool        $test         Whether the test mode is active
      *
      * @throws FileException         If file_uploads is disabled
      * @throws FileNotFoundException If the file does not exist
@@ -194,7 +194,7 @@ class UploadedFile extends File
     /**
      * Returns whether the file was uploaded successfully.
      *
-     * @return bool True if the file has been uploaded with HTTP and no error occurred.
+     * @return bool True if the file has been uploaded with HTTP and no error occurred
      */
     public function isValid()
     {