Fix for URL sanitization in `wp_kses_bad_protocol_once()`.

Merges [45997] to the 4.2 branch.

Props irsdl, sstoqnov, whyisjake.
Built from https://develop.svn.wordpress.org/branches/4.2@46012


git-svn-id: http://core.svn.wordpress.org/branches/4.2@45823 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/kses.php

@@ -1375,6 +1375,7 @@ function wp_kses_html_error($string) {
  * @return string Sanitized content
  */
 function wp_kses_bad_protocol_once($string, $allowed_protocols, $count = 1 ) {
+	$string  = preg_replace( '/(&#0*58(?![;0-9])|&#x0*3a(?![;a-f0-9]))/i', '$1;', $string );
 	$string2 = preg_split( '/:|&#0*58;|&#x0*3a;/i', $string, 2 );
 	if ( isset($string2[1]) && ! preg_match('%/\?%', $string2[0]) ) {
 		$string = trim( $string2[1] );