From 9734ed5673f6e7b3d8146c6bc7a0e8b82abe5d4a Mon Sep 17 00:00:00 2001
From: Sergey Biryukov <sergeybiryukov.ru@gmail.com>
Date: Wed, 16 Sep 2020 01:48:10 +0000
Subject: [PATCH] Code Modernization: Return an empty string from
 `wpdb::_real_escape()` if a non-scalar value is passed.

This avoids a fatal error on PHP 8 caused by passing a non-string value to ` mysqli_real_escape_string()`, and maintains the current behaviour.

See #50913, #50639.
Built from https://develop.svn.wordpress.org/trunk@48980


git-svn-id: http://core.svn.wordpress.org/trunk@48742 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/version.php | 2 +-
 wp-includes/wp-db.php   | 4 ++++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/wp-includes/version.php b/wp-includes/version.php
index 9ee377202b..7289f20059 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.6-alpha-48979';
+$wp_version = '5.6-alpha-48980';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.
diff --git a/wp-includes/wp-db.php b/wp-includes/wp-db.php
index 2e392d0954..9761de99a8 100644
--- a/wp-includes/wp-db.php
+++ b/wp-includes/wp-db.php
@@ -1159,6 +1159,10 @@ class wpdb {
 	 * @return string Escaped string.
 	 */
 	function _real_escape( $string ) {
+		if ( ! is_scalar( $string ) && ! is_null( $string ) ) {
+			return '';
+		}
+
 		if ( $this->dbh ) {
 			if ( $this->use_mysqli ) {
 				$escaped = mysqli_real_escape_string( $this->dbh, $string );