From: Aaron Schulz <aschulz@wikimedia.org>
Date: Wed, 15 Jun 2016 16:40:34 +0000 (-0700)
Subject: Fix WAN cache stashing bug due to missing list() call
X-Git-Tag: 1.31.0-rc.0~6601
X-Git-Url: http://git.cyclocoop.org/%22.%24h.%22?a=commitdiff_plain;h=fd4940a1b6120142d353f3e4e4062c5df1518a15;p=lhc%2Fweb%2Fwiklou.git

Fix WAN cache stashing bug due to missing list() call

Fixes regression from 0a38dbc809.

Bug: T137877
Change-Id: I4ea960966c084ada36dc54d4ec8729126c17ccdc
---

diff --git a/includes/libs/objectcache/WANObjectCache.php b/includes/libs/objectcache/WANObjectCache.php
index 45713cc814..ab702d57be 100644
--- a/includes/libs/objectcache/WANObjectCache.php
+++ b/includes/libs/objectcache/WANObjectCache.php
@@ -902,7 +902,7 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
 				// For hot keys, either another thread has the lock or the lock failed;
 				// use the INTERIM value from the last thread that regenerated it.
 				$wrapped = $this->cache->get( self::INTERIM_KEY_PREFIX . $key );
-				$value = $this->unwrap( $wrapped, microtime( true ) );
+				list( $value ) = $this->unwrap( $wrapped, microtime( true ) );
 				if ( $value !== false && $this->isValid( $value, $versioned, $asOf, $minTime ) ) {
 					$asOf = $wrapped[self::FLD_TIME];
 
diff --git a/tests/phpunit/includes/libs/objectcache/WANObjectCacheTest.php b/tests/phpunit/includes/libs/objectcache/WANObjectCacheTest.php
index 3a4aab487f..5bc1c8dbea 100644
--- a/tests/phpunit/includes/libs/objectcache/WANObjectCacheTest.php
+++ b/tests/phpunit/includes/libs/objectcache/WANObjectCacheTest.php
@@ -217,9 +217,23 @@ class WANObjectCacheTest extends MediaWikiTestCase {
 
 		// Acquire a lock to verify that getWithSetCallback uses lockTSE properly
 		$this->internalCache->lock( $key, 0 );
-		$ret = $cache->getWithSetCallback( $key, 30, $func, [ 'lockTSE' => 5 ] );
+
+		$checkKeys = [ wfRandomString() ]; // new check keys => force misses
+		$ret = $cache->getWithSetCallback( $key, 30, $func,
+			[ 'lockTSE' => 5, 'checkKeys' => $checkKeys ] );
 		$this->assertEquals( $value, $ret );
 		$this->assertEquals( 1, $calls, 'Callback was not used' );
+
+		$cache->delete( $key );
+		$ret = $cache->getWithSetCallback( $key, 30, $func,
+			[ 'lockTSE' => 5, 'checkKeys' => $checkKeys ] ); // should use interim value
+		$this->assertEquals( $value, $ret );
+		$this->assertEquals( 2, $calls, 'Callback was used' );
+
+		$ret = $cache->getWithSetCallback( $key, 30, $func,
+			[ 'lockTSE' => 5, 'checkKeys' => $checkKeys ] );
+		$this->assertEquals( $value, $ret );
+		$this->assertEquals( 2, $calls, 'Callback was not used; used interim' );
 	}
 
 	/**