From 911c76abcdfe89770b252eb0d4eb621c0db00ad5 Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@behdad.org>
Date: Fri, 6 Sep 2019 11:53:11 -0400
Subject: [PATCH] [null] Silence undefined-behavior complaints with too-small
 null bytes

Fixes https://bugzilla.mozilla.org/show_bug.cgi?id=1577584
---
 src/hb-null.hh | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/hb-null.hh b/src/hb-null.hh
index d4578205e..8657db349 100644
--- a/src/hb-null.hh
+++ b/src/hb-null.hh
@@ -48,8 +48,14 @@
 
 template <typename T, typename>
 struct _hb_null_size : hb_integral_constant<unsigned, sizeof (T)> {};
+#ifdef HB_TINY
+/* Disabled unless tiny, to avoid undefined-behavior.
+ * Enabling it saves a couple hundred bytes only.
+ * To make https://bugzilla.mozilla.org/show_bug.cgi?id=810823 happy.
+ */
 template <typename T>
 struct _hb_null_size<T, hb_void_t<decltype (T::min_size)>> : hb_integral_constant<unsigned, T::null_size> {};
+#endif
 
 template <typename T>
 using hb_null_size = _hb_null_size<T, void>;