From 011b458627db0c6832a7b8ef98b5fc87868ab82a Mon Sep 17 00:00:00 2001
From: Sam Smith <me@samsmith.io>
Date: Wed, 27 Dec 2017 14:17:04 +0000
Subject: [PATCH] Revision: Handle all return values of Title::newFromId

In Revision::getKnownCurrent, fail early when Title::newFromId returns
null to avoid an uncatchable fatal error being triggered.

RevisionStore#getKnownCurrentRevision requires that the title parameter
be an instance of Title.

This follows on from Ia4c20a91.

Change-Id: I9bddafcc5df630d1dff1e2526194186cab7097e5
---
 includes/Revision.php                         |  4 ++++
 tests/phpunit/includes/RevisionDbTestBase.php | 18 ++++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/includes/Revision.php b/includes/Revision.php
index 8f36e88fbe..b8b56a3f39 100644
--- a/includes/Revision.php
+++ b/includes/Revision.php
@@ -1204,6 +1204,10 @@ class Revision implements IDBAccessObject {
 			? $pageIdOrTitle
 			: Title::newFromID( $pageIdOrTitle );
 
+		if ( !$title ) {
+			return false;
+		}
+
 		$record = self::getRevisionStore()->getKnownCurrentRevision( $title, $revId );
 		return $record ? new Revision( $record ) : false;
 	}
diff --git a/tests/phpunit/includes/RevisionDbTestBase.php b/tests/phpunit/includes/RevisionDbTestBase.php
index 9ab76c8832..bd0dea6191 100644
--- a/tests/phpunit/includes/RevisionDbTestBase.php
+++ b/tests/phpunit/includes/RevisionDbTestBase.php
@@ -1363,6 +1363,24 @@ abstract class RevisionDbTestBase extends MediaWikiTestCase {
 		$this->assertEquals( $rev->getId(), $cachedRow->rev_id );
 	}
 
+	public function testNewKnownCurrent_withPageId() {
+		$db = wfGetDB( DB_MASTER );
+
+		$this->testPage->doEditContent( new WikitextContent( __METHOD__ ), __METHOD__ );
+		$rev = $this->testPage->getRevision();
+
+		$pageId = $this->testPage->getId();
+
+		$newRev = Revision::newKnownCurrent( $db, $pageId, $rev->getId() );
+		$this->assertRevEquals( $rev, $newRev );
+	}
+
+	public function testNewKnownCurrent_returnsFalseWhenTitleDoesntExist() {
+		$db = wfGetDB( DB_MASTER );
+
+		$this->assertFalse( Revision::newKnownCurrent( $db, 0 ) );
+	}
+
 	public function provideUserCanBitfield() {
 		yield [ 0, 0, [], null, true ];
 		// Bitfields match, user has no permissions
-- 
2.20.1