Index: schema.module
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/schema/schema.module,v
retrieving revision 1.43.2.9.2.11
diff -u -p -r1.43.2.9.2.11 schema.module
--- schema.module	17 May 2010 18:37:55 -0000	1.43.2.9.2.11
+++ schema.module	13 Jul 2010 18:03:03 -0000
@@ -611,11 +611,13 @@ function schema_compare() {
   // The info array is keyed by state (same/different/missing/extra/warn). For missing,
   // the value is a simple array of table names. For warn, it is a simple array of warnings.
   // Get those out of the way first
-  $warnings = $info['warn'];
-  foreach ($warnings as $message) {
-    drupal_set_message($message, 'warning');
+  if (isset($info['warn'])) {
+    $warnings = $info['warn'];
+    foreach ($warnings as $message) {
+      drupal_set_message($message, 'warning');
+    }
+    unset($info['warn']);
   }
-  unset($info['warn']);
 
   $form['extra'] = array(
     '#type' => 'fieldset',