Formatting: Allow KSES custom elements with hyphens

The W3C Custom Elements spec (http://www.w3.org/TR/custom-elements/#concepts) allows you to use your own custom DOM elements/tags. One of the main requirements is that the tag name "must contain a U+002D HYPHEN-MINUS character". This adjusts KSES to allow it.

Fixes #34105.
Props batmoo.


Built from https://develop.svn.wordpress.org/trunk@38511


git-svn-id: http://core.svn.wordpress.org/trunk@38452 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/kses.php

@@ -781,7 +781,7 @@ function wp_kses_split2($string, $allowed_html, $allowed_protocols) {
 	}
 	// Allow HTML comments
 
-	if (!preg_match('%^<\s*(/\s*)?([a-zA-Z0-9]+)([^>]*)>?$%', $string, $matches))
+	if (!preg_match('%^<\s*(/\s*)?([a-zA-Z0-9-]+)([^>]*)>?$%', $string, $matches))
 		return '';
 	// It's seriously malformed
 

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.7-alpha-38510';
+$wp_version = '4.7-alpha-38511';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.