Revisions: Ensure the global `$post` remains the same after revision is restored.

Because `wp_insert_post()` and `wp_transition_post_status()` are called during the process, plugins can unexpectedly modify `$post`.

Props markparnell, tofandel, archon810, SergeyBiryukov.
Fixes #46671.
Built from https://develop.svn.wordpress.org/trunk@48625


git-svn-id: http://core.svn.wordpress.org/trunk@48387 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/revision.php

@@ -60,8 +60,18 @@ switch ( $action ) {
 
 		check_admin_referer( "restore-post_{$revision->ID}" );
 
+		/*
+		 * Ensure the global $post remains the same after revision is restored.
+		 * Because wp_insert_post() and wp_transition_post_status() are called
+		 * during the process, plugins can unexpectedly modify $post.
+		 */
+		$backup_global_post = clone $post;
+
 		wp_restore_post_revision( $revision->ID );
 
+		// Restore the global $post as it was before.
+		$post = $backup_global_post;
+
 		$redirect = add_query_arg(
 			array(
 				'message'  => 5,

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.5-beta3-48624';
+$wp_version = '5.5-beta3-48625';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.