Index: formatting.php
===================================================================
--- formatting.php	(revision 18493)
+++ formatting.php	(working copy)
@@ -2246,16 +2246,16 @@
 
 	if ( '' == $url )
 		return $url;
-	$url = preg_replace('|[^a-z0-9-~+_.?#=!&;,/:%@$\|*\'()\\x80-\\xff]|i', '', $url);
-	$strip = array('%0d', '%0a', '%0D', '%0A');
-	$url = _deep_replace($strip, $url);
-	$url = str_replace(';//', '://', $url);
+	$url = preg_replace( '|[^a-z0-9-~+_.?#=!&;,/:%@$\|*\'()\\x80-\\xff]|i', '', $url );
+	$strip = array( '%0d', '%0a', '%0D', '%0A' );
+	$url = _deep_replace( $strip, $url );
+	$url = str_replace( ';//', '://', $url );
 	/* If the URL doesn't appear to contain a scheme, we
 	 * presume it needs http:// appended (unless a relative
 	 * link starting with /, # or ? or a php file).
 	 */
-	if ( strpos($url, ':') === false && ! in_array( $url[0], array( '/', '#', '?' ) ) &&
-		! preg_match('/^[a-z0-9-]+?\.php/i', $url) )
+	if ( strpos( $url, ':' ) === false && ! in_array( $url[0], array( '/', '#', '?' ) ) &&
+		! preg_match( '/^[a-z0-9-]+?\.php/i', $url ) )
 		$url = 'http://' . $url;
 
 	// Replace ampersands and single quotes only when displaying.
@@ -2265,12 +2265,12 @@
 		$url = str_replace( "'", ''', $url );
 	}
 
-	if ( !is_array($protocols) )
-		$protocols = array ('http', 'https', 'ftp', 'ftps', 'mailto', 'news', 'irc', 'gopher', 'nntp', 'feed', 'telnet', 'mms', 'rtsp', 'svn');
+	if ( ! is_array( $protocols ) )
+		$protocols = apply_filters( 'esc_url_protocols', array( 'http', 'https', 'ftp', 'ftps', 'mailto', 'news', 'irc', 'gopher', 'nntp', 'feed', 'telnet', 'mms', 'rtsp', 'svn', 'callto', 'tel', 'sms', 'fax', 'skype', 'git' ) );
 	if ( wp_kses_bad_protocol( $url, $protocols ) != $url )
 		return '';
 
-	return apply_filters('clean_url', $url, $original_url, $_context);
+	return apply_filters( 'clean_url', $url, $original_url, $_context );
 }
 
 /**