From 63e0d969b6f3347d25c8d5e416769ecb4f90ed3b Mon Sep 17 00:00:00 2001
From: Sergey Biryukov <sergeybiryukov@git.wordpress.org>
Date: Wed, 30 Sep 2020 12:07:13 +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.

git-svn-id: https://develop.svn.wordpress.org/trunk@49072 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-includes/wp-db.php | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/wp-includes/wp-db.php b/src/wp-includes/wp-db.php
index ebcadb6ef0..80c117c1a0 100644
--- a/src/wp-includes/wp-db.php
+++ b/src/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.