From e43ff0e9914941d635a898a1a04af87f76eb35cf Mon Sep 17 00:00:00 2001
From: Sergey Biryukov <sergeybiryukov.ru@gmail.com>
Date: Wed, 30 Sep 2020 12:09:08 +0000
Subject: [PATCH] Code Modernization: Return `false` from `wpdb::query()` if
 the query was filtered to an empty string using the `query` filter.

This avoids a fatal error on PHP 8 caused by passing an empty string to `mysqli_query()`, and maintains the current behaviour.

Follow-up to [48980], [48981].

See #50913, #50639.
Built from https://develop.svn.wordpress.org/trunk@49072


git-svn-id: http://core.svn.wordpress.org/trunk@48834 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/version.php | 2 +-
 wp-includes/wp-db.php   | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/wp-includes/version.php b/wp-includes/version.php
index f717b9c8c6..ff7dfb6f77 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.6-alpha-49071';
+$wp_version = '5.6-alpha-49072';
 
 /**
  * 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 ebcadb6ef0..80c117c1a0 100644
--- a/wp-includes/wp-db.php
+++ b/wp-includes/wp-db.php
@@ -1915,6 +1915,11 @@ class wpdb {
 		 */
 		$query = apply_filters( 'query', $query );
 
+		if ( ! $query ) {
+			$this->insert_id = 0;
+			return false;
+		}
+
 		$this->flush();
 
 		// Log how the function was called.