[serialize] Pass offset to serialize_copy()

src/hb-open-type.hh

@@ -320,17 +320,21 @@ struct OffsetTo : Offset<OffsetType, has_null>
 
   /* TODO: Somehow merge this with previous function into a serialize_dispatch(). */
   template <typename ...Ts>
-  bool serialize_copy (hb_serialize_context_t *c, const Type &src, const void *base, Ts&&... ds)
+  bool serialize_copy (hb_serialize_context_t *c,
+		       const OffsetTo& src,
+		       const void *src_base,
+		       const void *dst_base,
+		       Ts&&... ds)
   {
     *this = 0;
-    if (has_null && &src == _hb_has_null<Type, has_null>::get_null ())
+    if (src.is_null ())
       return false;
 
     c->push ();
 
-    bool ret = c->copy (src, hb_forward<Ts> (ds)...);
+    bool ret = c->copy (src_base+src, hb_forward<Ts> (ds)...);
 
-    c->add_link (*this, c->pop_pack (), base);
+    c->add_link (*this, c->pop_pack (), dst_base);
 
     return ret;
   }

src/hb-ot-layout-common.hh

@@ -279,10 +279,10 @@ struct Script
     TRACE_SUBSET (this);
     auto *out = c->serializer->embed (*this);
     if (unlikely (!out)) return_trace (false);
-    out->defaultLangSys.serialize_copy (c->serializer, this+defaultLangSys, out);
+    out->defaultLangSys.serialize_copy (c->serializer, defaultLangSys, this, out);
     unsigned int count = langSys.len;
     for (unsigned int i = 0; i < count; i++)
-      out->langSys.arrayZ[i].offset.serialize_copy (c->serializer, this+langSys[i].offset, out);
+      out->langSys.arrayZ[i].offset.serialize_copy (c->serializer, langSys[i].offset, this, out);
     return_trace (true);
   }
 

src/hb-ot-layout-gsubgpos.hh

@@ -2695,7 +2695,7 @@ struct GSUBGPOS
 			 out);
 
     if (version.to_int () >= 0x00010001u)
-     out->featureVars.serialize_copy (c->serializer, this+featureVars, out);
+     out->featureVars.serialize_copy (c->serializer, featureVars, this, out);
 
     return_trace (true);
   }

src/hb-ot-name-table.hh

@@ -104,7 +104,7 @@ struct NameRecord
     TRACE_SERIALIZE (this);
     auto *out = c->embed (this);
     if (unlikely (!out)) return_trace (nullptr);
-    out->offset.serialize_copy (c, src_base + offset, dst_base, length);
+    out->offset.serialize_copy (c, offset, src_base, dst_base, length);
     return_trace (out);
   }