Giovanni Mascellani : dwrite: Do not segfault when there are no typographic features to return.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 65f5033702780ce355749b09644df57c5305db33
URL:    https://source.winehq.org/git/wine.git/?a=commit;h=65f5033702780ce355749b09644df57c5305db33

Author: Giovanni Mascellani <gmascellani at codeweavers.com>
Date:   Wed Mar  3 15:25:28 2021 +0100

dwrite: Do not segfault when there are no typographic features to return.

Signed-off-by: Giovanni Mascellani <gmascellani at codeweavers.com>
Signed-off-by: Nikolay Sivov <nsivov at codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard at winehq.org>

---

 dlls/dwrite/shape.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/dlls/dwrite/shape.c b/dlls/dwrite/shape.c
index 6428bf6ceb0..abeb7eeac79 100644
--- a/dlls/dwrite/shape.c
+++ b/dlls/dwrite/shape.c
@@ -372,6 +372,12 @@ HRESULT shape_get_typographic_features(struct scriptshaping_context *context, co
     shape_get_script_lang_index(context, scripts, MS_GPOS_TAG, &script_index, &language_index);
     opentype_get_typographic_features(&context->cache->gpos, script_index, language_index, &t);
 
+    if (t.count == 0)
+    {
+        *actual_tagcount = 0;
+        return S_OK;
+    }
+
     /* Sort and remove duplicates. */
     qsort(t.tags, t.count, sizeof(*t.tags), tag_array_sorting_compare);