From abe33c6149719eb371c5f2b0d8c143550938129e Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@behdad.org>
Date: Mon, 1 Apr 2019 16:45:40 -0700
Subject: [PATCH] [serialize] Assert stack

---
 src/hb-serialize.hh | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/hb-serialize.hh b/src/hb-serialize.hh
index e3f8cc0..5eb27f0 100644
--- a/src/hb-serialize.hh
+++ b/src/hb-serialize.hh
@@ -227,6 +227,7 @@ struct hb_serialize_context_t
     if (unlikely (!objidx))
       return;
 
+    assert (current.length);
     unsigned i = current.length - 1;
     if (!base)
       base = current[i].head;
-- 
2.7.4