#885724 eliotttf: Avoid array_flip() on non scalars.

CHANGELOG.txt

@@ -3,6 +3,7 @@
 Feeds 6.x 1.0 XXXXXXXXXXXXXXXXXX
 --------------------------------
 
+- #885724 eliotttf: Avoid array_flip() on non scalars.
 - #885052 Hanno: Fix small typo in access rights.
 - #863494 ekes, alex_b: Delete temporary enclosures file.
 - #849986 lyricnz, alex_b: Cleaner batch support.

feeds.module

@@ -513,7 +513,7 @@ function _feeds_importer_digest() {
     else {
       $importers = array();
       foreach (feeds_importer_load_all() as $importer) {
-        $importers[$importer->id] = $importer->config['content_type'];
+        $importers[$importer->id] = isset($importer->config['content_type']) ? $importer->config['content_type'] : '';
       }
       cache_set(__FUNCTION__, $importers);
     }