[xserver] xfree86: fix Xorg memory leak when run xrandr

[Peter Hutterer]

On Mon, Feb 20, 2017 at 12:55:49PM -0600, Xiaogang Chen wrote:
> xf86DDCGetModes generates some DisplayMods that are not used and not released after.
> Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=99521
> 
> Signed-off-by: Xiaogang Chen <Xiaogang.Chen at amd.com>
> ---
>  hw/xfree86/modes/xf86EdidModes.c | 17 +++++------------
>  1 file changed, 5 insertions(+), 12 deletions(-)
> 
> diff --git a/hw/xfree86/modes/xf86EdidModes.c b/hw/xfree86/modes/xf86EdidModes.c
> index f0e1e97..915b291 100644
> --- a/hw/xfree86/modes/xf86EdidModes.c
> +++ b/hw/xfree86/modes/xf86EdidModes.c
> @@ -1201,18 +1201,11 @@ xf86EdidMonitorSet(int scrnIndex, MonPtr Monitor, xf86MonPtr DDC)
>          /* look for last Mode */
>          Mode = Modes;
>  
> -        while (Mode->next)
> -            Mode = Mode->next;
> +        /*release these video modes that are not used after*/
> +        while (Mode) {
> +           xf86DeleteMode(&Modes, Mode);
> +           Mode = Modes;
> +       }

this bit seems correct

>  
> -        /* add to MonPtr */
> -        if (Monitor->Modes) {
> -            Monitor->Last->next = Modes;
> -            Modes->prev = Monitor->Last;
> -            Monitor->Last = Mode;
> -        }
> -        else {
> -            Monitor->Modes = Modes;
> -            Monitor->Last = Mode;
> -        }

but why are you removing this bit? If that's intended, please expand your
commit message because right now it looks like these are two separate
changes.

Cheers,
   Peter