[PATCH xserver] xwayland: Make sure we have a focus window

[Peter Hutterer]

On Tue, Feb 28, 2017 at 02:27:52PM +0100, Olivier Fourdan wrote:
> During the InitInput() phase, the wayland events get dequeued so we
> can possibly end up calling dispatch_pointer_motion_event().
> 
> If this occurs before xwl_seat->focus_window is set, it leads to a NULL
> pointer derefence and a segfault.
> 
> Check for xwl_seat->focus_window in both pointer_handle_frame() and
> relative_pointer_handle_relative_motion() prior to calling
> dispatch_pointer_motion_event()  like it's done in
> pointer_handle_motion().
> 
> Bugzilla: https://bugzilla.redhat.com/1410804
> Signed-off-by: Olivier Fourdan <ofourdan at redhat.com>

remote: Updating patchwork state for https://patchwork.freedesktop.org/project/Xorg/list/
remote: I: patch #141238 updated using rev 8c9909a99292b2fb4a86de694bb0029f61e35662.
remote: I: 1 patch(es) updated to state Accepted.
To git+ssh://git.freedesktop.org/git/xorg/xserver
   c9cbdad..8c9909a  master -> master


Cheers,
   Peter

> ---
>  hw/xwayland/xwayland-input.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/hw/xwayland/xwayland-input.c b/hw/xwayland/xwayland-input.c
> index 8435da0..9c1581f 100644
> --- a/hw/xwayland/xwayland-input.c
> +++ b/hw/xwayland/xwayland-input.c
> @@ -510,6 +510,9 @@ pointer_handle_frame(void *data, struct wl_pointer *wl_pointer)
>  {
>      struct xwl_seat *xwl_seat = data;
>  
> +    if (!xwl_seat->focus_window)
> +        return;
> +
>      dispatch_pointer_motion_event(xwl_seat);
>  }
>  
> @@ -560,6 +563,9 @@ relative_pointer_handle_relative_motion(void *data,
>      xwl_seat->pending_pointer_event.dx_unaccel = wl_fixed_to_double(dx_unaccelf);
>      xwl_seat->pending_pointer_event.dy_unaccel = wl_fixed_to_double(dy_unaccelf);
>  
> +    if (!xwl_seat->focus_window)
> +        return;
> +
>      if (wl_proxy_get_version((struct wl_proxy *) xwl_seat->wl_pointer) < 5)
>          dispatch_pointer_motion_event(xwl_seat);
>  }
> -- 
> 2.9.3
>