#61433 by bozo, fix some logic around the GUID addition.

modules/aggregator/aggregator.module

@@ -859,12 +859,12 @@ function aggregator_parse_feed(&$data, $feed) {
     if ($item['LINK']) {
       $link = $item['LINK'];
     }
-    if ($item['GUID']) {
-      $guid = $item['GUID'];
-    }
     else {
       $link = $feed['link'];
     }
+    if ($item['GUID']) {
+      $guid = $item['GUID'];
+    }
 
     /**
      * Atom feeds have a CONTENT and/or SUMMARY tag instead of a DESCRIPTION tag