Merge "Update docblocks for methods potentially returning null"

diff --combined includes/EditPage.php
index 23d6ef9,02c395e..9d89785
--- 1/includes/EditPage.php
--- 2/includes/EditPage.php
+++ b/includes/EditPage.php
@@@ -25,7 -25,7 +25,7 @@@ use MediaWiki\EditPage\TextboxBuilder
  use MediaWiki\EditPage\TextConflictHelper;
  use MediaWiki\Logger\LoggerFactory;
  use MediaWiki\MediaWikiServices;
 -use MediaWiki\Storage\RevisionRecord;
 +use MediaWiki\Revision\RevisionRecord;
  use Wikimedia\ScopedCallback;
  
  /**
@@@ -2742,7 -2742,7 +2742,7 @@@ ERROR
         * content.
         *
         * @param Content|null|bool|string $content
-        * @return string The editable text form of the content.
+        * @return string|false|null The editable text form of the content.
         *
         * @throws MWException If $content is not an instance of TextContent and
         *   $this->allowNonTextContent is not true.