Ensure that channels can't be created with DAV reserved paths as a redress. Sabre mentions in several places that trying to change these paths to other strings; while possible - is unsupported and likely to cause problems. So for now, we're stuck with 'principals', 'addressbooks', and 'calendars'. If you already have these redresses on your site, you're basically buggered.

include/text.php

@@ -2025,7 +2025,7 @@ function check_webbie($arr) {
 	if(strlen($reservechan))
 		$taken = explode(',', $reservechan);
 	else
-		$taken = array();
+		$taken = array('principals','addressbooks','calendars');
 
 	$str = '';
 	if(count($arr)) {
@@ -2057,6 +2057,20 @@ function check_webbie($arr) {
 	return '';
 }
 
+function ids_to_array($arr,$idx = 'id') {
+	$t = array();
+	if($arr) {
+		foreach($arr as $x) {
+			if(! in_array($x[$idx],$t)) {
+				$t[] = $x[$idx];
+			}
+		}
+	}
+	return($t);
+}
+
+
+
 
 function ids_to_querystr($arr,$idx = 'id') {
 	$t = array();