user32: Fix bitmap_info_size to take into account bit field masks.

dlls/user32/cursoricon.c

@@ -223,7 +223,7 @@ static int get_dib_width_bytes( int width, int depth )
  */
 static int bitmap_info_size( const BITMAPINFO * info, WORD coloruse )
 {
-    int colors;
+    int colors, masks = 0;
 
     if (info->bmiHeader.biSize == sizeof(BITMAPCOREHEADER))
     {
@@ -239,7 +239,8 @@ static int bitmap_info_size( const BITMAPINFO * info, WORD coloruse )
                 colors = 256;
         if (!colors && (info->bmiHeader.biBitCount <= 8))
             colors = 1 << info->bmiHeader.biBitCount;
-        return sizeof(BITMAPINFOHEADER) + colors *
+        if (info->bmiHeader.biCompression == BI_BITFIELDS) masks = 3;
+        return sizeof(BITMAPINFOHEADER) + masks * sizeof(DWORD) + colors *
                ((coloruse == DIB_RGB_COLORS) ? sizeof(RGBQUAD) : sizeof(WORD));
     }
 }