From: daniel <daniel.kinzler@wikimedia.de>
Date: Mon, 6 Aug 2018 12:31:04 +0000 (+0200)
Subject: Add safeguard against loading content across wikis.
X-Git-Tag: 1.34.0-rc.0~4545^2
X-Git-Url: http://git.cyclocoop.org/?a=commitdiff_plain;h=25e9a28fd035bb5dccc72d2ebb9413f2d0fb5a39;p=lhc%2Fweb%2Fwiklou.git

Add safeguard against loading content across wikis.

The new MCR schema enables cross-wiki loading of page content,
but this mechanism doesn't work as long as the new code is reading from
the old schema. This is what caused T201194.

Bug: T201194
Change-Id: I58af7a9e02780c55cd8fab20f19be36a0fa804da
---

diff --git a/includes/Storage/RevisionStore.php b/includes/Storage/RevisionStore.php
index 65c0361b63..5769527796 100644
--- a/includes/Storage/RevisionStore.php
+++ b/includes/Storage/RevisionStore.php
@@ -207,6 +207,20 @@ class RevisionStore
 		return ( $this->mcrMigrationStage & $flags ) === $flags;
 	}
 
+	/**
+	 * Throws a RevisionAccessException if this RevisionStore is configured for cross-wiki loading
+	 * and still reading from the old DB schema.
+	 *
+	 * @throws RevisionAccessException
+	 */
+	private function assertCrossWikiContentLoadingIsSafe() {
+		if ( $this->wikiId !== false && $this->hasMcrSchemaFlags( SCHEMA_COMPAT_READ_OLD ) ) {
+			throw new RevisionAccessException(
+				"Cross-wiki content loading is not supported by the pre-MCR schema"
+			);
+		}
+	}
+
 	public function setLogger( LoggerInterface $logger ) {
 		$this->logger = $logger;
 	}
@@ -780,6 +794,8 @@ class RevisionStore
 
 			// MCR migration note: rev_content_model and rev_content_format will go away
 			if ( $this->contentHandlerUseDB ) {
+				$this->assertCrossWikiContentLoadingIsSafe();
+
 				$defaultModel = ContentHandler::getDefaultModelFor( $title );
 				$defaultFormat = ContentHandler::getForModelID( $defaultModel )->getDefaultFormat();
 
@@ -888,6 +904,8 @@ class RevisionStore
 			// if $wgContentHandlerUseDB is not set,
 			// all revisions must use the default content model and format.
 
+			$this->assertCrossWikiContentLoadingIsSafe();
+
 			$defaultModel = ContentHandler::getDefaultModelFor( $title );
 			$defaultHandler = ContentHandler::getForModelID( $defaultModel );
 			$defaultFormat = $defaultHandler->getDefaultFormat();
@@ -1207,6 +1225,8 @@ class RevisionStore
 
 		if ( $mainSlotRow->model_name === null ) {
 			$mainSlotRow->model_name = function ( SlotRecord $slot ) use ( $title ) {
+				$this->assertCrossWikiContentLoadingIsSafe();
+
 				// TODO: MCR: consider slot role in getDefaultModelFor()! Use LinkTarget!
 				// TODO: MCR: deprecate $title->getModel().
 				return ContentHandler::getDefaultModelFor( $title );
diff --git a/includes/Storage/RevisionStoreFactory.php b/includes/Storage/RevisionStoreFactory.php
index cfc544451a..9419b40939 100644
--- a/includes/Storage/RevisionStoreFactory.php
+++ b/includes/Storage/RevisionStoreFactory.php
@@ -75,7 +75,8 @@ class RevisionStoreFactory {
 	 * @param ActorMigration $actorMigration
 	 * @param int $migrationStage
 	 * @param LoggerSpi $loggerProvider
-	 * @param bool $contentHandlerUseDB see {@link $wgContentHandlerUseDB}
+	 * @param bool $contentHandlerUseDB see {@link $wgContentHandlerUseDB}. Must be the same
+	 *        for all wikis in the cluster. Will go away after MCR migration.
 	 */
 	public function __construct(
 		ILBFactory $dbLoadBalancerFactory,