From cae71f232cb466327f1e993a21b20b9ce7cb86a2 Mon Sep 17 00:00:00 2001
From: Peter Wilson <wilson@peterwilson.cc>
Date: Thu, 4 Nov 2021 23:56:58 +0000
Subject: [PATCH] Comments: Avoid reparenting during post deletion.

Delete comments in a descending order by comment ID when deleting a post.

This avoids the expense of additional database queries required to re-parent threaded comments that are themselves about to be deleted.

Props Mte90, andraganescu, johnbillion, hellofromTonya, peterwilsoncc.
Fixes #37703.


Built from https://develop.svn.wordpress.org/trunk@52015


git-svn-id: http://core.svn.wordpress.org/trunk@51606 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/post.php    | 4 ++--
 wp-includes/version.php | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/wp-includes/post.php b/wp-includes/post.php
index 0f75bf537e..b6ca7c24d3 100644
--- a/wp-includes/post.php
+++ b/wp-includes/post.php
@@ -3236,7 +3236,7 @@ function wp_delete_post( $postid = 0, $force_delete = false ) {
 
 	wp_defer_comment_counting( true );
 
-	$comment_ids = $wpdb->get_col( $wpdb->prepare( "SELECT comment_ID FROM $wpdb->comments WHERE comment_post_ID = %d", $postid ) );
+	$comment_ids = $wpdb->get_col( $wpdb->prepare( "SELECT comment_ID FROM $wpdb->comments WHERE comment_post_ID = %d ORDER BY comment_ID DESC", $postid ) );
 	foreach ( $comment_ids as $comment_id ) {
 		wp_delete_comment( $comment_id, true );
 	}
@@ -6194,7 +6194,7 @@ function wp_delete_attachment( $post_id, $force_delete = false ) {
 
 	wp_defer_comment_counting( true );
 
-	$comment_ids = $wpdb->get_col( $wpdb->prepare( "SELECT comment_ID FROM $wpdb->comments WHERE comment_post_ID = %d", $post_id ) );
+	$comment_ids = $wpdb->get_col( $wpdb->prepare( "SELECT comment_ID FROM $wpdb->comments WHERE comment_post_ID = %d ORDER BY comment_ID DESC", $post_id ) );
 	foreach ( $comment_ids as $comment_id ) {
 		wp_delete_comment( $comment_id, true );
 	}
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 2c8c21e10d..acb681e1d8 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.9-alpha-52014';
+$wp_version = '5.9-alpha-52015';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.