Re: Problems with compositing-enabled metacity in gnome enviroment

["Jan Djärv" <jan.h.d@swipnet.se>]

2011-02-11 15:53, Darren Hoo skrev:

> The version of  metacity I am using is 2.30.1-3 in Debian Unstable. Is
> there any related
> bug report of metacity that I can refer to?

No, but I guess you can file one.  BTW, I got 2.30.2-0 in ubuntu, and I always 
get the bug you see, even with emacs-23 that hasn't the commit you mention below.

>
> I had experienced the varnishes of  Gnome panel a long time ago, But
> since then I
> never experience it for at least half a year, aslo with  Chromium I
> never encounter
> such  symptoms as you mentioned.
>
> The only thing I want with compositing is the fancy tranparency of
> Emacs, switching to
> compiz seems not to be a choice for me, compiz is somewhat over-bloated to me.
>
>>
>> BTW, you probably meant (set-frame-parameter nil 'alpha 94).  Also, please
>> use report-emacs-bug for bugs like these.
> Got it
>
>> I reverted to the version before this commit, but the bug in metacity remains.  It is
>> probably a fluke that your meatcity works with>  that version.
>
> 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.

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

	Jan D.