Update core 8.3.0

web/core/modules/file/migration_templates/d6_file.yml

@@ -14,9 +14,10 @@ source:
     source_base_path: ''
 process:
     # If you are using both this migration and d6_user_picture_file in a custom
-    # migration and executing migrations incrementally, it is recommended that
-    # you remove the fid mapping here to avoid potential ID conflicts.
-  fid: fid
+    # migration and executing migrations incrementally, it is strongly
+    # recommended that you remove the fid mapping to avoid potential ID
+    # conflicts. For that reason, this mapping is commented out by default.
+    # fid: fid
   filename: filename
   source_full_path:
     -
@@ -40,7 +41,8 @@ process:
       - '@source_full_path'
       - '@destination_full_path'
   filemime: filemime
-  filesize: filesize
+  # No need to migrate filesize, it is computed when file entities are saved.
+  # filesize: filesize
   status: status
   changed: timestamp
   uid: uid