comctl32/listview: fix icon spacing calculation [try 2]

[Nikolay Sivov]

On 1/15/2013 01:15, Daniel Jelinski wrote:
> 2013/1/14 Nikolay Sivov <bunglehead at gmail.com>:
>> On 1/15/2013 00:53, Daniel Jelinski wrote:
>>
>>> +    if(lParam == -1)
>>> +      return LISTVIEW_SetIconSpacing(infoPtr, -1, -1);
>>> +    return LISTVIEW_SetIconSpacing(infoPtr, LOWORD(lParam),
>>> HIWORD(lParam));
>> Why do you need to handle this case specially? If it's -1 for 64bit comctl32
>> it should give you the same values with HIWORD/LOWORD as it does for 32bit.
> On 64bit the behavior with lParam=0xFFFFFFFF is different from that
> with lParam=-1. HIWORD/LOWORD values are the same, so without this
> special case they would behave the same way.
>
So on 64bit you want to distinguish two cases:
- ~0 value of lParam - you use it to reset to default values;
- all other values including 0xffffffff that will result in the same 
call with both args being -1.

So result is the same, right?

Your test:

> +#ifdef _WIN64
> +    ret = SendMessage(hwnd, LVM_SETICONSPACING, 0, 0xBAADF00DDEADBEEFLL);
> +    expect(0xFFFF, LOWORD(ret));
> +    expect(0xFFFF, HIWORD(ret));
> +    ret2 = SendMessage(hwnd, LVM_GETITEMSPACING, FALSE, 0);
> +    ok((LONG)0xDEADBEEF == ret2, "Expected FFFFFFFFDEADBEEF, got %p\n", (void*)ret2);
> +    ret2 = SendMessage(hwnd, LVM_SETICONSPACING, 0, -1);
> +    ok(0xDEADBEEF == ret2, "Expected 00000000DEADBEEF, got %p\n", (void*)ret2);
> +#endif
shows that higher DWORD is simply ignored, so value -1 and MAKELONG(-1, 
-1) should give same results.