From 7f326f92a5e4dd3b50195ed2cdcb56d8695ae0bc Mon Sep 17 00:00:00 2001
From: Sergey Biryukov <sergeybiryukov@git.wordpress.org>
Date: Sun, 16 Dec 2018 22:26:30 +0000
Subject: [PATCH] Block Editor: Prevent the meta box form from being
 accidentally submitted.

Meta boxes are loaded inside a wrapper form, that the block editor submits as part of the saving process. It shouldn't be submitted manually.

Props pento.
Merges [43880] to trunk.
Fixes #45284.

git-svn-id: https://develop.svn.wordpress.org/trunk@44240 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-admin/includes/post.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/wp-admin/includes/post.php b/src/wp-admin/includes/post.php
index 48caefa4d9..ced29d4a72 100644
--- a/src/wp-admin/includes/post.php
+++ b/src/wp-admin/includes/post.php
@@ -2210,7 +2210,7 @@ function the_block_editor_meta_boxes() {
 	<?php the_block_editor_meta_box_post_form_hidden_fields( $post ); ?>
 	</form>
 	<?php foreach ( $locations as $location ) : ?>
-		<form class="metabox-location-<?php echo esc_attr( $location ); ?>">
+		<form class="metabox-location-<?php echo esc_attr( $location ); ?>" onsubmit="return false;">
 			<div id="poststuff" class="sidebar-open">
 				<div id="postbox-container-2" class="postbox-container">
 					<?php