format_headlines_list: prevent warning on first_id changed check

classes/feeds.php

@@ -286,7 +286,7 @@ class Feeds extends Handler_Protected {
 
 		if ($_REQUEST["debug"]) $timing_info = print_checkpoint("H1", $timing_info);
 
-		$result = $qfh_ret[0];
+		$result = $qfh_ret[0]; // this could be either a PDO query result or a -1 if first id changed
 		$feed_title = $qfh_ret[1];
 		$feed_site_url = $qfh_ret[2];
 		$last_error = $qfh_ret[3];
@@ -318,6 +318,8 @@ class Feeds extends Handler_Protected {
         if ($_REQUEST["debug"]) $timing_info = print_checkpoint("PS", $timing_info);
         $expand_cdm = get_pref('CDM_EXPANDED');
 
+        if (is_object($result)) {
+
 			while ($line = $result->fetch()) {
 
 				++$headlines_count;
@@ -743,6 +745,7 @@ class Feeds extends Handler_Protected {
 
 				++$lnum;
 			}
+        }
 
         if ($_REQUEST["debug"]) $timing_info = print_checkpoint("PE", $timing_info);