gdi32: CreateBitmapIndirect should ignore the provided bm.bmWidthBytes

[Dmitry Timoshkov]

Hello,

Feng Yuan's book mentions an obscure fact that CreateBitmapIndirect ignores
the provided bm.bmWidthBytes and calculates it on its own. The test shows
that it's true.

Changelog:
    gdi32: CreateBitmapIndirect should ignore the provided bm.bmWidthBytes.

---
 dlls/gdi32/bitmap.c       |    3 +++
 dlls/gdi32/tests/bitmap.c |   14 ++++++++++++++
 2 files changed, 17 insertions(+), 0 deletions(-)

diff --git a/dlls/gdi32/bitmap.c b/dlls/gdi32/bitmap.c
index 22384de..e02a1f0 100644
--- a/dlls/gdi32/bitmap.c
+++ b/dlls/gdi32/bitmap.c
@@ -263,6 +263,9 @@ HBITMAP WINAPI CreateBitmapIndirect( const BITMAP *bmp )
         return NULL;
     }
 
+    /* Windows ignores the provided bm.bmWidthBytes */
+    bm.bmWidthBytes = BITMAP_GetWidthBytes( bm.bmWidth, bm.bmBitsPixel );
+
       /* Create the BITMAPOBJ */
     bmpobj = GDI_AllocObject( sizeof(BITMAPOBJ), BITMAP_MAGIC,
                               (HGDIOBJ *)&hbitmap, &bitmap_funcs );
diff --git a/dlls/gdi32/tests/bitmap.c b/dlls/gdi32/tests/bitmap.c
index ee4abc3..67f3e7c 100644
--- a/dlls/gdi32/tests/bitmap.c
+++ b/dlls/gdi32/tests/bitmap.c
@@ -1637,6 +1637,7 @@ static void test_mono_1x1_bmp_dbg(HBITMAP hbmp, int line)
 
 static void test_CreateBitmap(void)
 {
+    BITMAP bmp;
     HDC screenDC = GetDC(0);
     HDC hdc = CreateCompatibleDC(screenDC);
 
@@ -1684,6 +1685,19 @@ static void test_CreateBitmap(void)
 
     DeleteDC(hdc);
     ReleaseDC(0, screenDC);
+
+    /* show that Windows ignores the provided bm.bmWidthBytes */
+    bmp.bmType = 0;
+    bmp.bmWidth = 1;
+    bmp.bmHeight = 1;
+    bmp.bmWidthBytes = 28;
+    bmp.bmPlanes = 1;
+    bmp.bmBitsPixel = 1;
+    bmp.bmBits = NULL;
+    bm = CreateBitmapIndirect(&bmp);
+    ok(bm != 0, "CreateBitmapIndirect error %u\n", GetLastError());
+    test_mono_1x1_bmp(bm);
+    DeleteObject(bm);
 }
 
 START_TEST(bitmap)
-- 
1.5.0