[PATCH v2 1/1] user32: fix PNG cursor bitmap row alignment

[Jiajin Cui]

From: Jiajin Cui

Fixed bitmap row alignment calculation in PNG cursor loading to
ensure proper 32-bit DWORD alignment. Changed rowbytes calculation
from (width * bpp + 7) / 8 to (width * bpp + 31) / 32 * 4 for correct
byte alignment. Also fixed mask_size calculation to use proper DWORD
alignment. Removed the incorrect height doubling in biHeight field since
the bitmap and mask are now properly aligned and don't require separate
height allocation.

Signed-off-by: Jiajin Cui 
---
 dlls/user32/cursoricon.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/dlls/user32/cursoricon.c b/dlls/user32/cursoricon.c
index 552504accc4..2fbd949f4f2 100644
--- a/dlls/user32/cursoricon.c
+++ b/dlls/user32/cursoricon.c
@@ -383,10 +383,10 @@ static BITMAPINFO *load_png(const char *png_data, DWORD *size)
     width = png_get_image_width(png_ptr, info_ptr);
     height = png_get_image_height(png_ptr, info_ptr);

-    rowbytes = (width * bpp + 7) / 8;
+    rowbytes = (width * bpp + 31) / 32 * 4;
     image_size = height * rowbytes;
     if (bpp != 32) /* add a mask if there is no alpha */
-        mask_size = (width + 7) / 8 * height;
+        mask_size = (width + 31) / 32 * 4 * height;

info = RtlAllocateHeap(GetProcessHeap(), 0, sizeof(BITMAPINFOHEADER) + image_size + mask_size);
     if (!info)
@@ -416,7 +416,7 @@ static BITMAPINFO *load_png(const char *png_data, DWORD *size)

info->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
     info->bmiHeader.biWidth = width;
-    info->bmiHeader.biHeight = height * 2;
+    info->bmiHeader.biHeight = height;
     info->bmiHeader.biPlanes = 1;
     info->bmiHeader.biBitCount = bpp;
     info->bmiHeader.biCompression = BI_RGB;