From 48df8c3646e597738b74c73d56183005c00b4b4a Mon Sep 17 00:00:00 2001
From: Sergey Biryukov <sergeybiryukov@git.wordpress.org>
Date: Wed, 4 Mar 2020 12:03:32 +0000
Subject: [PATCH] General: Ensure `get_tag_regex()` always returns a string, to
 match the documented value.

Props subrataemfluence.
Fixes #45643.

git-svn-id: https://develop.svn.wordpress.org/trunk@47430 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-includes/functions.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/wp-includes/functions.php b/src/wp-includes/functions.php
index 658afaad3c..6c5184f697 100644
--- a/src/wp-includes/functions.php
+++ b/src/wp-includes/functions.php
@@ -6548,7 +6548,7 @@ function wp_auth_check( $response ) {
  */
 function get_tag_regex( $tag ) {
 	if ( empty( $tag ) ) {
-		return;
+		return '';
 	}
 	return sprintf( '<%1$s[^<]*(?:>[\s\S]*<\/%1$s>|\s*\/>)', tag_escape( $tag ) );
 }