Update Harfbuzz to version 6.0.0

Note: This requires an update to the tst_qtextlayout test, because
the test assumed that the Arabic string would always yield a run
of two glyphs. This was a side effect of how Harfbuzz handled
Qt's test font, which has zero font tables and cannot be used for
shaping. With the Harfbuzz update, the Arabic text here yields a
single cluster instead, which actually makes more sense, so the
test has been made a bit more robust to support both cases.

Pick-to: 6.2 6.5
Task-number: QTBUG-110338
Change-Id: I93d4cf8e3046dc93224e144d4c81d86bef4918d1
Reviewed-by: Lars Knoll <lars@knoll.priv.no>
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

1 files changed, 12 insertions, 3 deletions

diff --git a/src/3rdparty/harfbuzz-ng/src/hb-subset-repacker.cc b/src/3rdparty/harfbuzz-ng/src/hb-subset-repacker.cc
index 2447d296b8..55ca48d709 100644
--- a/src/3rdparty/harfbuzz-ng/src/hb-subset-repacker.cc
+++ b/src/3rdparty/harfbuzz-ng/src/hb-subset-repacker.cc
@@ -25,25 +25,34 @@
 #include "hb-repacker.hh"
 
 #ifdef HB_EXPERIMENTAL_API
+
 /**
  * hb_subset_repack_or_fail:
+ * @table_tag: tag of the table being packed, needed to allow table specific optimizations.
  * @hb_objects: raw array of struct hb_object_t, which provides
  * object graph info
  * @num_hb_objs: number of hb_object_t in the hb_objects array.
  *
  * Given the input object graph info, repack a table to eliminate
  * offset overflows. A nullptr is returned if the repacking attempt fails.
+ * Table specific optimizations (eg. extension promotion in GSUB/GPOS) may be performed.
+ * Passing HB_TAG_NONE will disable table specific optimizations.
  *
  * Since: EXPERIMENTAL
  **/
-hb_blob_t* hb_subset_repack_or_fail (hb_object_t* hb_objects, unsigned num_hb_objs)
+hb_blob_t* hb_subset_repack_or_fail (hb_tag_t table_tag,
+                                     hb_object_t* hb_objects,
+                                     unsigned num_hb_objs)
 {
   hb_vector_t<const hb_object_t *> packed;
   packed.alloc (num_hb_objs + 1);
   packed.push (nullptr);
   for (unsigned i = 0 ; i < num_hb_objs ; i++)
     packed.push (&(hb_objects[i]));
-  return hb_resolve_overflows (packed, HB_OT_TAG_GSUB);
+
+  return hb_resolve_overflows (packed,
+                               table_tag,
+                               20,
+                               true);
 }
 #endif
-