Options, Meta APIs: Use the correct escaping function when outputting the meta box context.

Props khaihong, abdullahramzan, leanderiversen, aryamaaru, lbenicio, palmiak

Fixes #44274

Built from https://develop.svn.wordpress.org/trunk@43365


git-svn-id: http://core.svn.wordpress.org/trunk@43193 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/includes/template.php

@@ -1099,7 +1099,7 @@ function do_meta_boxes( $screen, $context, $object ) {
 
 	$hidden = get_hidden_meta_boxes( $screen );
 
-	printf( '<div id="%s-sortables" class="meta-box-sortables">', htmlspecialchars( $context ) );
+	printf( '<div id="%s-sortables" class="meta-box-sortables">', esc_attr( $context ) );
 
 	// Grab the ones the user has manually sorted. Pull them out of their previous context/priority and into the one the user chose
 	if ( ! $already_sorted && $sorted = get_user_option( "meta-box-order_$page" ) ) {

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.0-alpha-43363';
+$wp_version = '5.0-alpha-43365';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.