[HarfBuzz] harfbuzz: Branch 'master' - 2 commits

[Behdad Esfahbod]

 src/hb-shaper-private.hh |    4 ++++
 src/hb-subset-plan.cc    |   12 ++++++++----
 2 files changed, 12 insertions(+), 4 deletions(-)

New commits:
commit bf90f35302c319ec4699ccbcd1e28b15ef2ec423
Author: Behdad Esfahbod <behdad at behdad.org>
Date:   Tue Jul 24 18:00:14 2018 -0700

    [coretext] Add note

diff --git a/src/hb-shaper-private.hh b/src/hb-shaper-private.hh
index ce2d9f28..3fa53216 100644
--- a/src/hb-shaper-private.hh
+++ b/src/hb-shaper-private.hh
@@ -97,6 +97,10 @@ HB_SHAPER_DATA_ENSURE_FUNC(shaper, object) (hb_##object##_t *object) \
   retry: \
   HB_SHAPER_DATA_TYPE (shaper, object) *data = (HB_SHAPER_DATA_TYPE (shaper, object) *) hb_atomic_ptr_get (&HB_SHAPER_DATA (shaper, object)); \
   if (likely (data) && !(condition)) { \
+    /* Note that evaluating condition above can be dangerous if another thread
+     * got here first and destructed data.  That's, as always, bad use pattern.
+     * If you modify the font (change font size), other threads must not be
+     * using it at the same time. */
     /* Drop and recreate. */ \
     /* If someone dropped it in the mean time, throw it away and don't touch it. \
      * Otherwise, destruct it. */ \
commit fb58cb4b5ca7043fa746b1a01790abf53bedfa86
Author: Garret Rieger <grieger at google.com>
Date:   Wed Jul 25 13:39:17 2018 -0700

    [subset] Only used reachable lookups for gsub closure.

diff --git a/src/hb-subset-plan.cc b/src/hb-subset-plan.cc
index 55c4e3f6..12566827 100644
--- a/src/hb-subset-plan.cc
+++ b/src/hb-subset-plan.cc
@@ -56,11 +56,15 @@ _add_gid_and_children (const OT::glyf::accelerator_t &glyf,
 static void
 _gsub_closure (hb_face_t *face, hb_set_t *gids_to_retain)
 {
-  // TODO(grieger): This uses all lookups, instead collect
-  //                the set of lookups that are relevant.
-  //                See fontTools implementation.
+  hb_auto_t<hb_set_t> lookup_indices;
+  hb_ot_layout_collect_lookups (face,
+                                HB_OT_TAG_GSUB,
+                                nullptr,
+                                nullptr,
+                                nullptr,
+                                &lookup_indices);
   hb_ot_layout_lookups_substitute_closure (face,
-                                           nullptr,
+                                           &lookup_indices,
                                            gids_to_retain);
 }