Ticket #25358: 25358.patch

wp-includes/class-wp.php

@@ -347 +347 @@
                                         )
                                 )
                         )
-                                $wp_last_modified = mysql2date('D, d M Y H:i:s', get_lastcommentmodified('GMT'), 0).' GMT';
-                        else
-                                $wp_last_modified = mysql2date('D, d M Y H:i:s', get_lastpostmodified('GMT'), 0).' GMT';
+                                $comment_last_modified = strtotime(get_lastcommentmodified('GMT'));
+                        $post_last_modified = strtotime(get_lastpostmodified('GMT'));
+                        $wp_last_modified = date('D, d M Y H:i:s', isset($comment_last_modified) && $comment_last_modified > $post_last_modified ? $comment_last_modified : $post_last_modified).' GMT';
                         $wp_etag = '"' . md5($wp_last_modified) . '"';
                         $headers['Last-Modified'] = $wp_last_modified;
                         $headers['ETag'] = $wp_etag;