Storage: Log when saveRevision() is hook-aborted

Gives some visibility into hooks like TemplateData onMultiContentSave,
which can prevent save due to syntax errors.  We want to understand
how often this happens, and under what circumstances.

Configuration should be set to log the SavePage channel at debug
level.

Bug: T305821
Change-Id: Idfac599182c216e5bdb405d3722e68a50d8b9168

includes/Storage/PageUpdater.php

@@ -50,6 +50,7 @@ use MediaWiki\User\UserEditTracker;
 use MediaWiki\User\UserGroupManager;
 use MediaWiki\User\UserIdentity;
 use MWException;
+use Psr\Log\LoggerInterface;
 use RecentChange;
 use RuntimeException;
 use Status;
@@ -210,6 +211,9 @@ class PageUpdater {
 	/** @var string[] */
 	private $softwareTags = [];
 
+	/** @var LoggerInterface */
+	private $logger;
+
 	/**
 	 * @param UserIdentity $author
 	 * @param WikiPage $wikiPage
@@ -225,6 +229,7 @@ class PageUpdater {
 	 * @param ServiceOptions $serviceOptions
 	 * @param string[] $softwareTags Array of currently enabled software change tags. Can be
 	 *        obtained from ChangeTags::getSoftwareTags()
+	 * @param LoggerInterface $logger
 	 */
 	public function __construct(
 		UserIdentity $author,
@@ -239,7 +244,8 @@ class PageUpdater {
 		UserGroupManager $userGroupManager,
 		TitleFormatter $titleFormatter,
 		ServiceOptions $serviceOptions,
-		array $softwareTags
+		array $softwareTags,
+		LoggerInterface $logger
 	) {
 		$serviceOptions->assertRequiredOptions( self::CONSTRUCTOR_OPTIONS );
 		$this->serviceOptions = $serviceOptions;
@@ -271,6 +277,7 @@ class PageUpdater {
 			)
 		);
 		$this->softwareTags = $softwareTags;
+		$this->logger = $logger;
 	}
 
 	/**
@@ -916,6 +923,7 @@ class PageUpdater {
 			}
 
 			$this->status = $hookStatus;
+			$this->logger->info( "Hook prevented page save", [ 'status' => $hookStatus ] );
 			return null;
 		}
 

includes/Storage/PageUpdaterFactory.php

@@ -283,7 +283,8 @@ class PageUpdaterFactory {
 				PageUpdater::CONSTRUCTOR_OPTIONS,
 				$this->options
 			),
-			$this->softwareTags
+			$this->softwareTags,
+			$this->logger
 		);
 
 		$pageUpdater->setUsePageCreationLog(