From da0f9cd6fbf1d8156e0f39837f7d381f46d9e942 Mon Sep 17 00:00:00 2001
From: Sergey Biryukov <sergeybiryukov@git.wordpress.org>
Date: Sun, 28 Jul 2019 17:51:34 +0000
Subject: [PATCH] Rewrite Rules: Check if `$wp_rewrite->flush_rules()` is
 callable before calling it in `flush_rewrite_rules()`.

Props bsetiawan88, markjaquith.
Fixes #47087.

git-svn-id: https://develop.svn.wordpress.org/trunk@45699 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-includes/rewrite.php | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/wp-includes/rewrite.php b/src/wp-includes/rewrite.php
index a03754f272..2666ff6f97 100644
--- a/src/wp-includes/rewrite.php
+++ b/src/wp-includes/rewrite.php
@@ -273,7 +273,10 @@ function add_feed( $feedname, $function ) {
  */
 function flush_rewrite_rules( $hard = true ) {
 	global $wp_rewrite;
-	$wp_rewrite->flush_rules( $hard );
+
+	if ( is_callable( array( $wp_rewrite, 'flush_rules' ) ) ) {
+		$wp_rewrite->flush_rules( $hard );
+	}
 }
 
 /**