Index: includes/theme.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/theme.inc,v
retrieving revision 1.420
diff -u -r1.420 theme.inc
--- includes/theme.inc	14 Apr 2008 17:48:33 -0000	1.420
+++ includes/theme.inc	28 Apr 2008 23:59:26 -0000
@@ -247,8 +247,8 @@
 
 /**
  * Process a single invocation of the theme hook. $type will be one
- * of 'module', 'theme_engine' or 'theme' and it tells us some
- * important information.
+ * of 'module', 'theme_engine', 'base_theme_engine', 'theme', or 'base_theme'
+ * and it tells us some important information.
  *
  * Because $cache is a reference, the cache will be continually
  * expanded upon; new entries will replace old entries in the
@@ -314,7 +314,7 @@
           // to provide preprocess functions even if they are not the owner of the current hook.
           $prefixes += module_list();
         }
-        elseif ($type == 'theme_engine') {
+        elseif ($type == 'theme_engine' || $type == 'base_theme_engine') {
           // Theme engines get an extra set that come before the normally named preprocessors.
           $prefixes[] = $name . '_engine';
           // The theme engine also registers on behalf of the theme. The theme or engine name can be used.
@@ -373,7 +373,7 @@
 
   // Process each base theme.
   foreach ($base_theme as $base) {
-    // If the theme uses a theme engine, process its hooks.
+    // If the base theme uses a theme engine, process its hooks.
     $base_path = dirname($base->filename);
     if ($theme_engine) {
       _theme_process_registry($cache, $theme_engine, 'base_theme_engine', $base->name, $base_path);