Index: includes/theme.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/theme.inc,v
retrieving revision 1.622
diff -u -p -b -r1.622 theme.inc
--- includes/theme.inc	30 Oct 2010 03:57:20 -0000	1.622
+++ includes/theme.inc	16 Nov 2010 03:36:40 -0000
@@ -823,19 +823,30 @@ function theme($hook, $variables = array
   // Invoke the variable processors, if any. The processors may specify
   // alternate suggestions for which hook's template/function to use. If the
   // hook is a suggestion of a base hook, invoke the variable processors of
-  // the base hook, but retain the suggestion as a high priority suggestion to
-  // be used unless overridden by a variable processor function.
+  // the base hook.
+  $variables['theme_hook_suggestions'] = array();
   if (isset($info['base hook'])) {
     $base_hook = $info['base hook'];
     $base_hook_info = $hooks[$base_hook];
+
     if (isset($base_hook_info['preprocess functions']) || isset($base_hook_info['process functions'])) {
       $variables['theme_hook_suggestion'] = $hook;
-      $hook = $base_hook;
-      $info = $base_hook_info;
+      foreach (array('preprocess functions', 'process functions') as $phase) {
+        if (!empty($base_hook_info[$phase])) {
+          foreach ($base_hook_info[$phase] as $processor_function) {
+            if (function_exists($processor_function)) {
+              // We don't want a poorly behaved process function changing $hook.
+              $hook_clone = $base_hook;
+              $processor_function($variables, $hook_clone);
+            }
+          }
     }
   }
+    }
+  }
+
+  // Run any preprocess and process functions belonging to this hook.
   if (isset($info['preprocess functions']) || isset($info['process functions'])) {
-    $variables['theme_hook_suggestions'] = array();
     foreach (array('preprocess functions', 'process functions') as $phase) {
       if (!empty($info[$phase])) {
         foreach ($info[$phase] as $processor_function) {
@@ -847,6 +858,8 @@ function theme($hook, $variables = array
         }
       }
     }
+  }
+
     // If the preprocess/process functions specified hook suggestions, and the
     // suggestion exists in the theme registry, use it instead of the hook that
     // theme() was called with. This allows the preprocess/process step to
@@ -872,7 +885,6 @@ function theme($hook, $variables = array
         break;
       }
     }
-  }
 
   // Generate the output using either a function or a template.
   $output = '';