1 files changed, 23 insertions, 0 deletions
diff --git a/classes/User_im_prefs.php b/classes/User_im_prefs.php
index 8ecdfe9fa..75be8969e 100644
--- a/classes/User_im_prefs.php
+++ b/classes/User_im_prefs.php
@@ -68,4 +68,27 @@ class User_im_prefs extends Memcached_DataObject
     {
         return array(false,false);
     }
+
+    /**
+     * We have two compound keys with unique constraints:
+     * (transport, user_id) which is our primary key, and
+     * (transport, screenname) which is an additional constraint.
+     * 
+     * Currently there's not a way to represent that second key
+     * in the general keys list, so we're adding it here to the
+     * list of keys to use for caching, ensuring that it gets
+     * cleared as well when we change.
+     * 
+     * @return array of cache keys
+     */
+    function _allCacheKeys()
+    {
+        $ukeys = 'transport,screenname';
+        $uvals = $this->transport . ',' . $this->screenname;
+
+        $ckeys = parent::_allCacheKeys();
+        $ckeys[] = $this->cacheKey($this->tableName(), $ukeys, $uvals);
+        return $ckeys;
+    }
+
 }