[PATCH 0/1] MR5568: windowscodecs: Avoid implicit cast changing value.

[Alistair Leslie-Hughes (＠alesliehughes)]

This appear to be introduced with commit 12f73ed9d851.

When This->stride is negative (bottom up image) it converts the multiplication to an UINT.
Thus causing the pointer to be incorrect when y > 0.

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/5568

[PATCH 1/1] windowscodecs: Avoid implicit cast changing value.

[Alistair Leslie-Hughes]

From: Alistair Leslie-Hughes <leslie_alistair(a)hotmail.com>

This appear to be introduced with commit 12f73ed9d851.

When This->stride is negative (bottom up image) it converts the multiplication to an UINT.
Thus causing the pointer to be incorrect when y > 0.
---
 dlls/windowscodecs/bmpdecode.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dlls/windowscodecs/bmpdecode.c b/dlls/windowscodecs/bmpdecode.c
index 9d4867447f0..ae6feda5b50 100644
--- a/dlls/windowscodecs/bmpdecode.c
+++ b/dlls/windowscodecs/bmpdecode.c
@@ -432,7 +432,7 @@ static HRESULT BmpFrameDecode_ReadABGRasBGR(BmpDecoder* This)
     {
         for (y = 0; y < height; y++)
         {
-            pixel = This->imagedatastart + This->stride * y;
+            pixel = This->imagedatastart + This->stride * (INT)y;
 
             for (x = 0; x < width; x++)
             {
-- 
GitLab

https://gitlab.winehq.org/wine/wine/-/merge_requests/5568

[Piotr Caban (＠piotr)]

The code was copied from `reverse_bgr8` helper so it has similar problem.

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/5568#note_69398