From c233f2c90b9a27aee715c7d3653763dd5e26d4c9 Mon Sep 17 00:00:00 2001
From: Lukas Reschke <lukas@owncloud.com>
Date: Tue, 17 Mar 2015 11:56:00 +0100
Subject: [PATCH] Add version and path to cache prefix

Prevents to have the cache reused by other instances on the server which have possible the same instance ID and also invalidates older cache entries after an upgrade which can cause unwanted side-effects.

Impact for deployment: The same cache will only get used if ownCloud is installed with the same version and under the same path. But this should be a basic requirement anyways.
---
 lib/private/memcache/cache.php | 3 +++
 lib/private/server.php         | 7 ++++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/lib/private/memcache/cache.php b/lib/private/memcache/cache.php
index c606d94fa5..d2d0353feb 100644
--- a/lib/private/memcache/cache.php
+++ b/lib/private/memcache/cache.php
@@ -21,6 +21,9 @@ abstract class Cache implements \ArrayAccess, \OCP\ICache {
 		$this->prefix = $prefix;
 	}
 
+	/**
+	 * @return string Prefix used for caching purposes
+	 */
 	public function getPrefix() {
 		return $this->prefix;
 	}
diff --git a/lib/private/server.php b/lib/private/server.php
index 2f688c47f0..6261337e0b 100644
--- a/lib/private/server.php
+++ b/lib/private/server.php
@@ -157,8 +157,13 @@ class Server extends SimpleContainer implements IServerContainer {
 		});
 		$this->registerService('MemCacheFactory', function ($c) {
 			$config = $c->getConfig();
+			$v = \OC_App::getAppVersions();
+			$v['core'] = implode('.', \OC_Util::getVersion());
+			$version = implode(',', $v);
 			$instanceId = \OC_Util::getInstanceId();
-			return new \OC\Memcache\Factory($instanceId,
+			$path = \OC::$SERVERROOT;
+			$prefix = md5($instanceId.'-'.$version.'-'.$path);
+			return new \OC\Memcache\Factory($prefix,
 				$config->getSystemValue('memcache.local', null),
 				$config->getSystemValue('memcache.distributed', null)
 			);