Short circuit if indices list is empty

diff --git a/imp/lib/Imap/Thread.php b/imp/lib/Imap/Thread.php
index aa09f91..b7c9cd3 100644 (file)
--- a/imp/lib/Imap/Thread.php
+++ b/imp/lib/Imap/Thread.php
@@ -55,6 +55,10 @@ class IMP_Imap_Thread
         $thread_level = $tree = array();
         $t = &$this->_thread;
 
+        if (empty($indices)) {
+            return $tree;
+        }
+
         $indices = array_intersect($t->messageList($sortdir), $indices);
 
         /* If starting in the middle of a thread, the threadLevel tree needs