From 8ca796ea999b32a7525caddb3ed2febdf53b5bda Mon Sep 17 00:00:00 2001
From: Matthias Mullie <git@mullie.eu>
Date: Mon, 28 Sep 2015 09:55:28 +0200
Subject: [PATCH] Fix Memcached key decode

Flow had a key: flowdb:flow_ref:wiki:by-source:v3:Parser\'s_"broken"_+_(page)_&_grill:testwiki:1:4.7
the '+' in there was not being encoded (it only does /[\x00-\x20\x25\x7f]+/)
but coming back, it was decoded into ' '.
getMulti() shows a key=>value array or results. Since key was different,
we couldn't find what we had requested.

Bug: T110326
Change-Id: Ia92edd73d0eb7fe0d35e38e7e7af8174fb85cbcc
---
 includes/objectcache/MemcachedBagOStuff.php          | 5 ++++-
 tests/phpunit/includes/objectcache/BagOStuffTest.php | 8 ++++++--
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/includes/objectcache/MemcachedBagOStuff.php b/includes/objectcache/MemcachedBagOStuff.php
index e545aa55a6..7d1274921c 100644
--- a/includes/objectcache/MemcachedBagOStuff.php
+++ b/includes/objectcache/MemcachedBagOStuff.php
@@ -168,7 +168,10 @@ class MemcachedBagOStuff extends BagOStuff {
 	 * @return string
 	 */
 	public function decodeKey( $key ) {
-		return urldecode( $key );
+		// matches %00-%20, %25, %7F (=decoded alternatives for those encoded in encodeKey)
+		return preg_replace_callback( '/%([0-1][0-9]|20|25|7F)/i', function ( $match ) {
+			return urldecode( $match[0] );
+		}, $key );
 	}
 
 	/**
diff --git a/tests/phpunit/includes/objectcache/BagOStuffTest.php b/tests/phpunit/includes/objectcache/BagOStuffTest.php
index b684006202..cde7ed680e 100644
--- a/tests/phpunit/includes/objectcache/BagOStuffTest.php
+++ b/tests/phpunit/includes/objectcache/BagOStuffTest.php
@@ -139,24 +139,28 @@ class BagOStuffTest extends MediaWikiTestCase {
 		$value1 = array( 'this' => 'is', 'a' => 'test' );
 		$value2 = array( 'this' => 'is', 'another' => 'test' );
 		$value3 = array( 'testing a key that may be encoded when sent to cache backend' );
+		$value4 = array( 'another test where chars in key will be encoded' );
 
 		$key1 = wfMemcKey( 'test1' );
 		$key2 = wfMemcKey( 'test2' );
 		$key3 = wfMemcKey( 'will-%-encode' ); // internally, MemcachedBagOStuffs will encode to will-%25-encode
+		$key4 = wfMemcKey( 'flowdb:flow_ref:wiki:by-source:v3:Parser\'s_"broken"_+_(page)_&_grill:testwiki:1:4.7' );
 
 		$this->cache->add( $key1, $value1 );
 		$this->cache->add( $key2, $value2 );
 		$this->cache->add( $key3, $value3 );
+		$this->cache->add( $key4, $value4 );
 
 		$this->assertEquals(
-			array( $key1 => $value1, $key2 => $value2, $key3 => $value3 ),
-			$this->cache->getMulti( array( $key1, $key2, $key3 ) )
+			array( $key1 => $value1, $key2 => $value2, $key3 => $value3, $key4 => $value4 ),
+			$this->cache->getMulti( array( $key1, $key2, $key3, $key4 ) )
 		);
 
 		// cleanup
 		$this->cache->delete( $key1 );
 		$this->cache->delete( $key2 );
 		$this->cache->delete( $key3 );
+		$this->cache->delete( $key4 );
 	}
 
 	/**
-- 
2.20.1