[PATCH 1/1] gdi32: Don't stackoverflow if substitute doesn't change anything

[Fabian Maurer]

From: Fabian Maurer

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=53787
Signed-off-by: Fabian Maurer 
---
 dlls/gdi32/uniscribe/opentype.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/dlls/gdi32/uniscribe/opentype.c b/dlls/gdi32/uniscribe/opentype.c
index c44639cb993..718bff767f9 100644
--- a/dlls/gdi32/uniscribe/opentype.c
+++ b/dlls/gdi32/uniscribe/opentype.c
@@ -894,6 +894,8 @@ static INT GSUB_apply_SingleSubst(const OT_LookupTable *look, WORD *glyphs, INT
             if (GSUB_is_glyph_covered((const BYTE*)ssf1+offset, glyphs[glyph_index]) != -1)
             {
                 TRACE("  Glyph 0x%x ->",glyphs[glyph_index]);
+                if (GET_BE_WORD(ssf1->DeltaGlyphID) == 0)
+                    return GSUB_E_NOGLYPH;
                 glyphs[glyph_index] = glyphs[glyph_index] + GET_BE_WORD(ssf1->DeltaGlyphID);
                 TRACE(" 0x%x\n",glyphs[glyph_index]);
                 return glyph_index + write_dir;