Re: Problems with compositing-enabled metacity in gnome enviroment

[Darren Hoo]

Hi Jan,

On Sat, Feb 12, 2011 at 12:02 AM, Jan Djärv <address@hidden> wrote:
>> just FYI,  it is this specific hunk of the commit that triggers the
>> (possible) bug of metacity
>> Just revert this hunk of the commit Emacs works as expected at least for
>> me.
>>
>> src/xterm.c:
>>
>> @@ -489,14 +489,14 @@ x_set_frame_alpha (struct frame *f)
>>                        &data);
>>
>>      if (rc == Success&&  actual != None)
>> -      if (*(unsigned long *)data == opac)
>> -       {
>> -         XFree ((void *) data);
>> -         x_uncatch_errors ();
>> -         return;
>> -       }
>> -      else
>> +      {
>>        XFree ((void *) data);
>> +       if (*(unsigned long *)data == opac)
>> +         {
>> +           x_uncatch_errors ();
>> +           return;
>> +         }
>> +      }
>>      x_uncatch_errors ();
>>    }
>
> Ouch, this looks really bad.  Not only is data accesses after it has been
> free:d, but we may be doing catch errors twice and uncatch only once.

Yes, comparsion after data has been freed,  it does not return and continues
to execute  XChangeProperty afterwards.

>
> I fixed this, see if it works with your metacity.  It doesn't for me.

I double checked this, revert this hunk works for me.


Darren.