? sites/default/files
? sites/default/settings.php
Index: includes/bootstrap.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/bootstrap.inc,v
retrieving revision 1.315
diff -u -p -r1.315 bootstrap.inc
--- includes/bootstrap.inc	26 Oct 2009 13:00:54 -0000	1.315
+++ includes/bootstrap.inc	28 Oct 2009 23:41:54 -0000
@@ -1806,7 +1806,10 @@ function drupal_get_schema($table = NULL
       require_once DRUPAL_ROOT . '/includes/common.inc';
       // Invoke hook_schema for all modules.
       foreach (module_implements('schema') as $module) {
-        $current = module_invoke($module, 'schema');
+        // Cast the result of hook_schema() to an array, as a NULL return value
+        // would cause array_merge() to set the $schema variable to NULL as well.
+        // That would break modules which use $schema further down the line.
+        $current = (array) module_invoke($module, 'schema');
         _drupal_schema_initialize($module, $current);
         $schema = array_merge($schema, $current);
       }