check count before foreach

include/conversation.php

@@ -918,6 +918,7 @@ function conv_sort($arr,$order) {
 	$ret = array();
 	foreach($parents as $x) {
 		$ret[] = $x;
+		if(count($x['children']))
 			foreach($x['children'] as $y)
 				$ret[] = $y;
 	}