[Spice-devel] [PATCH spice-gtk] main: use stable comparison function for monitors

[Hans de Goede]

Hi,

On 02/20/2013 06:09 PM, Hans de Goede wrote:
> Hi,
>
> On 02/20/2013 11:35 AM, Marc-André Lureau wrote:
>> If monitors are equal, compare them by their addresses, to get the
>> effect of a stable sort.
>> ---
>>   gtk/channel-main.c | 3 ++-
>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/gtk/channel-main.c b/gtk/channel-main.c
>> index fe57684..f86e81d 100644
>> --- a/gtk/channel-main.c
>> +++ b/gtk/channel-main.c
>> @@ -973,8 +973,9 @@ static int monitors_cmp(const void *p1, const void *p2, gpointer user_data)
>>       const VDAgentMonConfig *m2 = p2;
>>       double d1 = sqrt(m1->x * m1->x + m1->y * m1->y);
>>       double d2 = sqrt(m2->x * m2->x + m2->y * m2->y);
>> +    int diff = d1 - d2;
>>
>> -    return d1 - d2;
>> +    return diff == 0 ? (char*)p1 - (char*)p2 : diff;
>
> I think that should be: "(char*)p2 - (char*)p1" So that if the
> address of p2 is bigger they compare as p2 > p1, and qsort will
> keep the order of the array the same for monitors with identical
> coordinates.

After further discussion, it turns out I'm wrong. So ACK for the patch
as is.

Regards,

Hans