commit eafd515639497098436ecf4c7b836e231bced323
author Behdad Esfahbod <behdad@behdad.org> Fri Nov 16 14:45:56 2018 -0800
committer Behdad Esfahbod <behdad@behdad.org> Fri Nov 16 14:45:56 2018 -0800
tree f062ea93e1d509089233a7bdfc8f83c8b780460c
parent aa06574823e27c4dbb378d2467a3e6f6f36af9fe

Prefer morx table if GSUB is empty (no scripts)

Fixes https://github.com/harfbuzz/harfbuzz/issues/1348

src/hb-ot-shape.cc

diff --git a/src/hb-ot-shape.cc b/src/hb-ot-shape.cc
index 093511e..00d4c0b 100644
--- a/src/hb-ot-shape.cc
+++ b/src/hb-ot-shape.cc
@@ -62,7 +62,11 @@
       hb_aat_layout_has_substitution (face))
     return true;
 
-  return !hb_ot_layout_has_substitution (face) &&
+  /* Ignore empty GSUB tables. */
+  return (!hb_ot_layout_has_substitution (face) ||
+	  !hb_ot_layout_table_get_script_tags (face,
+					       HB_OT_TAG_GSUB,
+					       0, nullptr, nullptr)) &&
 	 hb_aat_layout_has_substitution (face);
 }