Nikolay Sivov : dwrite: Fix character range to glyph range matching for user features.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: d4784a9211a18f247e1698f79d1dd02338df068a
URL:    https://source.winehq.org/git/wine.git/?a=commit;h=d4784a9211a18f247e1698f79d1dd02338df068a

Author: Nikolay Sivov <nsivov at codeweavers.com>
Date:   Wed Feb 17 13:33:23 2021 +0300

dwrite: Fix character range to glyph range matching for user features.

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

---

 dlls/dwrite/opentype.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/dlls/dwrite/opentype.c b/dlls/dwrite/opentype.c
index 125b7353031..39943c52c9a 100644
--- a/dlls/dwrite/opentype.c
+++ b/dlls/dwrite/opentype.c
@@ -4733,7 +4733,7 @@ static void opentype_layout_get_glyph_range_for_text(struct scriptshaping_contex
     if (end_char >= context->length - 1)
         *end_glyph = context->glyph_count - 1;
     else
-        *end_glyph = context->u.buffer.clustermap[end_char + 1] - 1;
+        *end_glyph = context->u.buffer.clustermap[end_char] - 1;
 }
 
 static void opentype_layout_set_glyph_masks(struct scriptshaping_context *context, const struct shaping_features *features)
@@ -4754,6 +4754,9 @@ static void opentype_layout_set_glyph_masks(struct scriptshaping_context *contex
        if (start_char >= context->length)
            break;
 
+       if (!context->user_features.range_lengths[r])
+           continue;
+
        opentype_layout_get_glyph_range_for_text(context, start_char, start_char + context->user_features.range_lengths[r],
                &start_glyph, &end_glyph);
        start_char += context->user_features.range_lengths[r];