Horde_Cache wants strings, so use '' instead of null

diff --git a/framework/Db/lib/Horde/Db/Adapter/Base/Schema.php b/framework/Db/lib/Horde/Db/Adapter/Base/Schema.php
index 9c09236..49ac475 100644 (file)
--- a/framework/Db/lib/Horde/Db/Adapter/Base/Schema.php
+++ b/framework/Db/lib/Horde/Db/Adapter/Base/Schema.php
@@ -803,8 +803,7 @@ abstract class Horde_Db_Adapter_Base_Schema
      */
     protected function _clearTableCache($tableName)
     {
-        $this->_cache->set("tables/columns/$tableName", null);
-        $this->_cache->set("tables/indexes/$tableName", null);
+        $this->_cache->set("tables/columns/$tableName", '');
+        $this->_cache->set("tables/indexes/$tableName", '');
     }
-
 }