Index: includes/actions.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/actions.inc,v
retrieving revision 1.16
diff -u -p -r1.16 actions.inc
--- includes/actions.inc	5 Sep 2008 09:29:06 -0000	1.16
+++ includes/actions.inc	13 Sep 2008 14:26:05 -0000
@@ -78,12 +78,16 @@ function actions_do($action_ids, $object
     foreach ($actions as $action_id => $params) {
       if (is_numeric($action_id)) { // Configurable actions need parameters.
         $function = $params['callback'];
-        $context = array_merge($context, $params);
-        $result[$action_id] = $function($object, $context, $a1, $a2);
+        if (drupal_function_exists($function)) {
+          $context = array_merge($context, $params);
+          $result[$action_id] = $function($object, $context, $a1, $a2);
+        }
       }
       // Singleton action; $action_id is the function name.
       else {
-        $result[$action_id] = $action_id($object, $context, $a1, $a2);
+        if (drupal_function_exists($action_id)) {
+          $result[$action_id] = $action_id($object, $context, $a1, $a2);
+        }
       }
     }
   }
@@ -93,12 +97,16 @@ function actions_do($action_ids, $object
     if (is_numeric($action_ids)) {
       $action = db_fetch_object(db_query("SELECT * FROM {actions} WHERE aid = '%s'", $action_ids));
       $function = $action->callback;
-      $context = array_merge($context, unserialize($action->parameters));
-      $result[$action_ids] = $function($object, $context, $a1, $a2);
+      if (drupal_function_exists($function)) {
+        $context = array_merge($context, unserialize($action->parameters));
+        $result[$action_ids] = $function($object, $context, $a1, $a2);
+      }
     }
     // Singleton action; $action_ids is the function name.
     else {
-      $result[$action_ids] = $action_ids($object, $context, $a1, $a2);
+      if (drupal_function_exists($action_ids)) {
+        $result[$action_ids] = $action_ids($object, $context, $a1, $a2);
+      }
     }
   }
   return $result;
@@ -236,7 +244,7 @@ function actions_function_lookup($hash) 
   }
 
   // Must be an instance; must check database.
-  $aid = db_result(db_query("SELECT aid FROM {actions} WHERE MD5(aid) = '%s' AND parameters <> ''", $hash));
+  $aid = db_result(db_query("SELECT aid FROM {actions} WHERE MD5(aid) = '%s'", $hash));
   return $aid;
 }