From 4cbc7d61bc5e7f0658fc58d807f94f3b7c335f0d Mon Sep 17 00:00:00 2001
From: Garret Rieger <grieger@google.com>
Date: Thu, 30 Jul 2020 12:20:31 -0700
Subject: [PATCH] [ENOMEM] check for unset current in serializer->length().

---
 src/hb-serialize.hh | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/hb-serialize.hh b/src/hb-serialize.hh
index 43aea3897..d8c61f412 100644
--- a/src/hb-serialize.hh
+++ b/src/hb-serialize.hh
@@ -373,7 +373,11 @@ struct hb_serialize_context_t
       }
   }
 
-  unsigned int length () const { return this->head - current->head; }
+  unsigned int length () const
+  {
+    if (unlikely (!current)) return 0;
+    return this->head - current->head;
+  }
 
   void align (unsigned int alignment)
   {