Index: includes/context.inc
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/drush/includes/context.inc,v
retrieving revision 1.3
diff -u -p -r1.3 context.inc
--- includes/context.inc	26 Mar 2009 01:41:21 -0000	1.3
+++ includes/context.inc	29 Mar 2009 18:28:53 -0000
@@ -90,7 +90,7 @@ function _drush_config_file($context) {
   // TODO: This really should be a proper, system-wide location.
   $configs['drush'] = dirname(__FILE__) . '/../drushrc.php';
 
-  return $configs[$context];
+  return array_key_exists($context, $configs) ? $configs[$context] : NULL;
 }