TinyMCE: add lang attribute

This is needed to make `hyphens: auto;` work correctly.

Fixes #32555.

Built from https://develop.svn.wordpress.org/trunk@35217


git-svn-id: http://core.svn.wordpress.org/trunk@35183 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/class-wp-editor.php

@@ -543,6 +543,7 @@ final class _WP_Editors {
 					'wpeditimage_disable_captions' => $no_captions,
 					'wpeditimage_html5_captions' => current_theme_supports( 'html5', 'caption' ),
 					'plugins' => implode( ',', $plugins ),
+					'wp_lang_attr' => get_bloginfo( 'language' )
 				);
 
 				if ( ! empty( $mce_external_plugins ) ) {

wp-includes/js/tinymce/plugins/wordpress/plugin.js

@@ -428,6 +428,8 @@ tinymce.PluginManager.add( 'wordpress', function( editor ) {
 			dom.setAttrib( doc.documentElement, 'dir', 'rtl' );
 		}
 
+		dom.setAttrib( doc.documentElement, 'lang', editor.getParam( 'wp_lang_attr' ) );
+
 		if ( env.ie ) {
 			if ( parseInt( env.ie, 10 ) === 9 ) {
 				bodyClass.push('ie9');

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.4-alpha-35216';
+$wp_version = '4.4-alpha-35217';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.