From 35458b6b66f801194a1dad957308be9a71280425 Mon Sep 17 00:00:00 2001
From: Garret Rieger <grieger@google.com>
Date: Fri, 11 Jun 2021 13:14:51 -0700
Subject: [PATCH] [subset] Add serialize_serialize to OffsetTo.

Similar to serialize_subset() this will serialize the new object and then link it to the offset.
---
 src/hb-open-type.hh            | 17 +++++++++++++++++
 src/hb-ot-layout-gsub-table.hh |  2 +-
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/src/hb-open-type.hh b/src/hb-open-type.hh
index 42eb8af05..a1ff423ca 100644
--- a/src/hb-open-type.hh
+++ b/src/hb-open-type.hh
@@ -355,6 +355,23 @@ struct OffsetTo : Offset<OffsetType, has_null>
     return ret;
   }
 
+
+  template <typename ...Ts>
+  bool serialize_serialize (hb_serialize_context_t *c, Ts&&... ds)
+  {
+    *this = 0;
+
+    Type* obj = c->push<Type> ();
+    bool ret = obj->serialize (c, hb_forward<Ts> (ds)...);
+
+    if (ret)
+      c->add_link (*this, c->pop_pack ());
+    else
+      c->pop_discard ();
+
+    return ret;
+  }
+
   /* TODO: Somehow merge this with previous function into a serialize_dispatch(). */
   /* Workaround clang bug: https://bugs.llvm.org/show_bug.cgi?id=23029
    * Can't compile: whence = hb_serialize_context_t::Head followed by Ts&&...
diff --git a/src/hb-ot-layout-gsub-table.hh b/src/hb-ot-layout-gsub-table.hh
index 25538d52f..ae57cbb10 100644
--- a/src/hb-ot-layout-gsub-table.hh
+++ b/src/hb-ot-layout-gsub-table.hh
@@ -101,7 +101,7 @@ struct SingleSubstFormat1
   {
     TRACE_SERIALIZE (this);
     if (unlikely (!c->extend_min (*this))) return_trace (false);
-    if (unlikely (!coverage.serialize (c, this).serialize (c, glyphs))) return_trace (false);
+    if (unlikely (!coverage.serialize_serialize (c, glyphs))) return_trace (false);
     c->check_assign (deltaGlyphID, delta, HB_SERIALIZE_ERROR_INT_OVERFLOW);
     return_trace (true);
   }