From ccbd16fef10fc88a790ccd56e0c44f2740243d34 Mon Sep 17 00:00:00 2001
From: Sergey Biryukov <sergeybiryukov.ru@gmail.com>
Date: Thu, 19 Aug 2021 12:44:57 +0000
Subject: [PATCH] Media: Check the return type of `_get_cron_array()` in
 `WP_Media_List_Table::prepare_items()`.
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The following warnings could, in very select circumstances, be shown:
{{{
// PHP 8.0 and higher:
Warning: foreach() argument must be of type array|object, bool given

// PHP 5.6 – 7.4
Warning: Invalid argument supplied for foreach()
}}}

In `WP_Media_List_Table::prepare_items()`, the cron info array is retrieved via a call to `_get_cron_array()`, but as the documentation (correctly) states, the return type of that function is `array|false`, where `false` is returned for a virgin site, with no cron jobs scheduled yet.

However, no type check is done on the return value, and the method just blindly continues by using it in a `foreach`.

Fixed by adding validation for the returned value from `_get_cron_array()` and only running the `foreach` when the returned value is an array.

Reference: [https://developer.wordpress.org/reference/functions/_get_cron_array/ WordPress Developer Resources: _get_cron_array()]

Follow-up to [48417].

Props jrf, hellofromTonya, mukesh27.
Fixes #53949.
Built from https://develop.svn.wordpress.org/trunk@51638


git-svn-id: http://core.svn.wordpress.org/trunk@51244 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-admin/includes/class-wp-media-list-table.php | 14 +++++++++-----
 wp-includes/version.php                         |  2 +-
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/wp-admin/includes/class-wp-media-list-table.php b/wp-admin/includes/class-wp-media-list-table.php
index b3eb0b32cc..275d07caca 100644
--- a/wp-admin/includes/class-wp-media-list-table.php
+++ b/wp-admin/includes/class-wp-media-list-table.php
@@ -78,12 +78,16 @@ class WP_Media_List_Table extends WP_List_Table {
 		 */
 		$not_in = array();
 
-		foreach ( _get_cron_array() as $cron ) {
-			if ( isset( $cron['upgrader_scheduled_cleanup'] ) ) {
-				$details = reset( $cron['upgrader_scheduled_cleanup'] );
+		$crons = _get_cron_array();
 
-				if ( ! empty( $details['args'][0] ) ) {
-					$not_in[] = (int) $details['args'][0];
+		if ( is_array( $crons ) ) {
+			foreach ( $crons as $cron ) {
+				if ( isset( $cron['upgrader_scheduled_cleanup'] ) ) {
+					$details = reset( $cron['upgrader_scheduled_cleanup'] );
+
+					if ( ! empty( $details['args'][0] ) ) {
+						$not_in[] = (int) $details['args'][0];
+					}
 				}
 			}
 		}
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 2c931ecfc2..71bf87b302 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.9-alpha-51637';
+$wp_version = '5.9-alpha-51638';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.