Remove workaround for comparing database domain IDs.

Change-Id: I240d68eddec871794ed98b7ce67773114ee73ff7

includes/Storage/RevisionStore.php

@@ -1484,29 +1484,13 @@ class RevisionStore implements IDBAccessObject, RevisionFactory, RevisionLookup
 	 * @throws MWException
 	 */
 	private function checkDatabaseWikiId( IDatabase $db ) {
-		$storeWiki = $this->wikiId;
+		$storeWiki = $this->loadBalancer->getLocalDomainID();
 		$dbWiki = $db->getDomainID();
 
 		if ( $dbWiki === $storeWiki ) {
 			return;
 		}
 
-		// XXX: we really want the default database ID...
-		$storeWiki = $storeWiki ?: wfWikiID();
-		$dbWiki = $dbWiki ?: wfWikiID();
-
-		if ( $dbWiki === $storeWiki ) {
-			return;
-		}
-
-		// HACK: counteract encoding imposed by DatabaseDomain
-		$storeWiki = str_replace( '?h', '-', $storeWiki );
-		$dbWiki = str_replace( '?h', '-', $dbWiki );
-
-		if ( $dbWiki === $storeWiki ) {
-			return;
-		}
-
 		throw new MWException( "RevisionStore for $storeWiki "
 			. "cannot be used with a DB connection for $dbWiki" );
 	}

tests/phpunit/includes/Storage/RevisionStoreDbTest.php

@@ -22,6 +22,7 @@ use TestUserRegistry;
 use Title;
 use WANObjectCache;
 use Wikimedia\Rdbms\Database;
+use Wikimedia\Rdbms\DatabaseDomain;
 use Wikimedia\Rdbms\DatabaseSqlite;
 use Wikimedia\Rdbms\FakeResultWrapper;
 use Wikimedia\Rdbms\LoadBalancer;
@@ -40,7 +41,12 @@ class RevisionStoreDbTest extends MediaWikiTestCase {
 	private function getLoadBalancerMock( array $server ) {
 		$lb = $this->getMockBuilder( LoadBalancer::class )
 			->setMethods( [ 'reallyOpenConnection' ] )
-			->setConstructorArgs( [ [ 'servers' => [ $server ] ] ] )
+			->setConstructorArgs( [ [
+				'servers' => [ $server ],
+				'localDomain' => new DatabaseDomain(
+					$server['dbname'], null, $server['tablePrefix']
+				),
+			] ] )
 			->getMock();
 
 		$lb->method( 'reallyOpenConnection' )->willReturnCallback(