- Patch #852362 by chx: fixed extend is 100% fubar.

includes/database/database.inc

@@ -646,7 +646,7 @@ protected function expandArguments(&$query, &$args) {
    * @return string
    *   The name of the class that should be used for this driver.
    */
-  protected function getDriverClass($class) {
+  public function getDriverClass($class) {
     if (empty($this->driverClasses[$class])) {
       $this->driverClasses[$class] = $class . '_' . $this->driver();
       if (!class_exists($this->driverClasses[$class])) {

includes/database/select.inc

@@ -601,11 +601,8 @@ public function havingCompile(DatabaseConnection $connection) {
   /* Implementations of QueryExtendableInterface. */
 
   public function extend($extender_name) {
-    $override_class = $this->connection->driver();
-    if (class_exists($override_class)) {
-      $extender_name = $override_class;
-    }
-    return new $extender_name($this, $this->connection);
+    $class = $this->connection->getDriverClass($extender_name);
+    return new $class($this, $this->connection);
   }
 
   /* Alter accessors to expose the query data to alter hooks. */