From 3f4764bb56bb7e42ba8859f1905810bd2f998838 Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@behdad.org>
Date: Mon, 30 Jul 2012 10:06:42 -0400
Subject: [PATCH] Don't lock user_data set during destruction if empty

---
 src/hb-private.hh | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/hb-private.hh b/src/hb-private.hh
index ea3254c..2f85025 100644
--- a/src/hb-private.hh
+++ b/src/hb-private.hh
@@ -442,6 +442,11 @@ struct hb_lockable_set_t
 
   inline void finish (lock_t &l)
   {
+    if (!items.len) {
+      /* No need for locking. */
+      items.finish ();
+      return;
+    }
     l.lock ();
     while (items.len) {
       item_t old = items[items.len - 1];
-- 
2.7.4