From 8cd601c8ba6a6a16949ae0cb626921f3169ce7b8 Mon Sep 17 00:00:00 2001
From: Sergey Biryukov <sergeybiryukov.ru@gmail.com>
Date: Tue, 27 Apr 2021 18:36:04 +0000
Subject: [PATCH] REST API: Check the results of `get_metadata()` in
 `WP_REST_Meta_Fields` methods.

This avoids PHP warnings in case the function returns boolean `false` instead of an array.

Props david.binda.
Fixes #53099.
Built from https://develop.svn.wordpress.org/trunk@50793


git-svn-id: http://core.svn.wordpress.org/trunk@50402 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 .../rest-api/fields/class-wp-rest-meta-fields.php  | 14 +++++++++++---
 wp-includes/version.php                            |  2 +-
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/wp-includes/rest-api/fields/class-wp-rest-meta-fields.php b/wp-includes/rest-api/fields/class-wp-rest-meta-fields.php
index 817f5c106a..f186648545 100644
--- a/wp-includes/rest-api/fields/class-wp-rest-meta-fields.php
+++ b/wp-includes/rest-api/fields/class-wp-rest-meta-fields.php
@@ -94,8 +94,10 @@ abstract class WP_REST_Meta_Fields {
 			} else {
 				$value = array();
 
-				foreach ( $all_values as $row ) {
-					$value[] = $this->prepare_value_for_response( $row, $request, $args );
+				if ( is_array( $all_values ) ) {
+					foreach ( $all_values as $row ) {
+						$value[] = $this->prepare_value_for_response( $row, $request, $args );
+					}
 				}
 			}
 
@@ -281,6 +283,10 @@ abstract class WP_REST_Meta_Fields {
 		$current_values = get_metadata( $meta_type, $object_id, $meta_key, false );
 		$subtype        = get_object_subtype( $meta_type, $object_id );
 
+		if ( ! is_array( $current_values ) ) {
+			$current_values = array();
+		}
+
 		$to_remove = $current_values;
 		$to_add    = $values;
 
@@ -377,7 +383,9 @@ abstract class WP_REST_Meta_Fields {
 		$old_value = get_metadata( $meta_type, $object_id, $meta_key );
 		$subtype   = get_object_subtype( $meta_type, $object_id );
 
-		if ( 1 === count( $old_value ) && $this->is_meta_value_same_as_stored_value( $meta_key, $subtype, $old_value[0], $value ) ) {
+		if ( is_array( $old_value ) && 1 === count( $old_value )
+			&& $this->is_meta_value_same_as_stored_value( $meta_key, $subtype, $old_value[0], $value )
+		) {
 			return true;
 		}
 
diff --git a/wp-includes/version.php b/wp-includes/version.php
index f0233bc13b..4ec6f8d22b 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.8-alpha-50792';
+$wp_version = '5.8-alpha-50793';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.