msvfw32: Fix uncompressed bitmap size handling in DrawDibDraw.

dlls/msvfw32/drawdib.c

@@ -355,12 +355,6 @@ BOOL VFWAPI DrawDibDraw(HDRAWDIB hdd, HDC hdc,
 
     if (!(wFlags & DDF_UPDATE)) 
     {
-        DWORD biSizeImage = lpbi->biSizeImage;
-
-        /* biSizeImage may be set to 0 for BI_RGB (uncompressed) bitmaps */
-        if ((lpbi->biCompression == BI_RGB) && (biSizeImage == 0))
-            biSizeImage = ((lpbi->biWidth * lpbi->biBitCount + 31) / 32) * 4 * lpbi->biHeight;
-
         if (lpbi->biCompression) 
         {
             DWORD flags = 0;
@@ -374,6 +368,8 @@ BOOL VFWAPI DrawDibDraw(HDRAWDIB hdd, HDC hdc,
         }
         else
         {
+            /* BI_RGB: lpbi->biSizeImage isn't reliable */
+            DWORD biSizeImage = ((lpbi->biWidth * lpbi->biBitCount + 31) / 32) * 4 * lpbi->biHeight;
             memcpy(whdd->lpvbits, lpBits, biSizeImage);
         }
     }

dlls/msvfw32/tests/drawdib.c

@@ -105,6 +105,12 @@ static void test_DrawDib_sizeimage(void)
         {      0,        0, 0, "" },
         {      0,   HEIGHT, 0, "" },
         {  WIDTH,        0, 0, "" },
+        /* [8] zero size (to compare [9], [10] ) */
+        {  WIDTH, HEIGHT/2, 0, "8b75bf6d54a8645380114fe77505ee0699ffffaa" },
+        /* [9] insufficient size */
+        {  WIDTH, HEIGHT/2, sizeof(RGBQUAD), "8b75bf6d54a8645380114fe77505ee0699ffffaa" },
+        /* [10] too much size */
+        {  WIDTH, HEIGHT/2, WIDTH * HEIGHT * sizeof(RGBQUAD), "8b75bf6d54a8645380114fe77505ee0699ffffaa" },
     };
     HDC hdc;
     DWORD src_dib_size, dst_dib_size;