user32: fix potential crash when loading unsupported files (with tests) (try 2) (resend)

[Alexandre Julliard]

Vitaly Perov <vitperov at etersoft.ru> writes:

> @@ -1238,6 +1260,12 @@ static void test_LoadImage(void)
>      test_LoadImageFile("JPG", jpgimage, sizeof(jpgimage), "jpg", 0);
>      test_LoadImageFile("PNG", pngimage, sizeof(pngimage), "png", 0);
>  
> +    /* Corrupted images */
> +    test_LoadCorruptedImageFile("corrupted_BMP", bmpimage, sizeof(bmpimage), "bmp", 1);
> +    test_LoadCorruptedImageFile("corrupted_GIF", gifimage, sizeof(gifimage), "gif", 0);
> +    test_LoadCorruptedImageFile("corrupted_JPG", jpgimage, sizeof(jpgimage), "jpg", 0);
> +    test_LoadCorruptedImageFile("corrupted_PNG", pngimage, sizeof(pngimage), "png", 0);
> +

That's an interesting test, but it has nothing to do with your fix. We
shouldn't crash on loading corrupted files, but we shouldn't crash if
idReserved is 0 either. Your proposed fix is just hiding the problem.

Checking idReserved may or may not be a good idea, independently of
fixing that crash, but that would need a different test.

-- 
Alexandre Julliard
julliard at winehq.org