From 0b9c7b7cdf860a046c4ee7ffd676c420b6ac7a0b Mon Sep 17 00:00:00 2001
From: Peter Wilson <wilson@peterwilson.cc>
Date: Mon, 22 Feb 2021 00:51:09 +0000
Subject: [PATCH] Site Health: Update loopback test to `POST` to wp-cron.

Replace loopback health check URL with a `POST` request to `wp-cron.php` in the WordPress install directory. This more closely represents how WordPress uses loopback requests.

A `POST` request is used to cause `wp-cron.php` to exit prior to running any cron jobs. This allows the test to indicate success quicker and accounts for sites that set the `DISABLE_WP_CRON` constant to avoid running cron jobs on loopback requests.

Props clorith, peterwilsoncc, TimothyBlynJacobs.
Fixes #52547.


Built from https://develop.svn.wordpress.org/trunk@50399


git-svn-id: http://core.svn.wordpress.org/trunk@50010 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-admin/includes/class-wp-site-health.php | 15 +++++++++++++--
 wp-includes/version.php                    |  2 +-
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/wp-admin/includes/class-wp-site-health.php b/wp-admin/includes/class-wp-site-health.php
index bae01e7af9..48bd21b6a6 100644
--- a/wp-admin/includes/class-wp-site-health.php
+++ b/wp-admin/includes/class-wp-site-health.php
@@ -2647,6 +2647,7 @@ class WP_Site_Health {
 	 * @return object The test results.
 	 */
 	function can_perform_loopback() {
+		$body    = array( 'site-health' => 'loopback-test' );
 		$cookies = wp_unslash( $_COOKIE );
 		$timeout = 10;
 		$headers = array(
@@ -2660,9 +2661,19 @@ class WP_Site_Health {
 			$headers['Authorization'] = 'Basic ' . base64_encode( wp_unslash( $_SERVER['PHP_AUTH_USER'] ) . ':' . wp_unslash( $_SERVER['PHP_AUTH_PW'] ) );
 		}
 
-		$url = home_url();
+		$url = site_url( 'wp-cron.php' );
 
-		$r = wp_remote_get( $url, compact( 'cookies', 'headers', 'timeout', 'sslverify' ) );
+		/*
+		 * A post request is used for the wp-cron.php loopback test to cause the file
+		 * to finish early without triggering cron jobs. This has two benefits:
+		 * - cron jobs are not triggered a second time on the site health page,
+		 * - the loopback request finishes sooner providing a quicker result.
+		 *
+		 * Using a POST request causes the loopback to differ slightly to the standard
+		 * GET request WordPress uses for wp-cron.php loopback requests but is close
+		 * enough. See https://core.trac.wordpress.org/ticket/52547
+		 */
+		$r = wp_remote_post( $url, compact( 'body', 'cookies', 'headers', 'timeout', 'sslverify' ) );
 
 		if ( is_wp_error( $r ) ) {
 			return (object) array(
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 3a705494cb..b57cd77cec 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.7-beta3-50398';
+$wp_version = '5.7-beta3-50399';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.