Issue #2150989 by chilic | osopolar: SimpleTest fails: Undefined index:...

Issue #2150989 by chilic | osopolar: SimpleTest fails: Undefined index: content-type, Notice file: http_request.inc Line: 57.

libraries/http_request.inc

@@ -54,7 +54,7 @@ function http_request_get_common_syndication($url, $settings = NULL) {
   // @see http_request_get.
   $downloaded_string = $download->data;
   // If this happens to be a feed then just return the url.
-  if (http_request_is_feed($download->headers['content-type'], $downloaded_string)) {
+  if (isset($download->headers['content-type']) && http_request_is_feed($download->headers['content-type'], $downloaded_string)) {
     return $url;
   }