[PATCH xserver] xwayland: remove dirty window unconditionally on unrealize

[Daniel Stone]

Hi Olivier,

On 24 January 2018 at 16:45, Olivier Fourdan <ofourdan at redhat.com> wrote:
> This is a rare occurrence of a crash in Xwayland for which I don't have
> the reproducing steps, just a core file.
>
> The backtrace looks as follow:
>   [...]
>
> The crash is caused by dereferencing “xwl_pixmap->buffer” in
> xwl_glamor_pixmap_get_wl_buffer() because “xwl_pixmap” is NULL.
>
> Reason for this is because the corresponding pixmap is from the root
> window and xwayland is rootless by default.
>
> This can happen if the window was mapped, redirected, damaged and
> unredirected immediately, before the damage is processed by Xwayland.
>
> Make sure to remove the dirty window from the damage list on unrealize
> to prevent this from happening.
>
> Credit goes to Adam Jackson <ajax at nwnk.net> and Daniel Stone
> <daniel at fooishbar.org> for finding the root cause the issue.
>
> Signed-off-by: Olivier Fourdan <ofourdan at redhat.com>

This is also:
Reviewed-by: Daniel Stone <daniels at collabora.com>

Cheers,
Daniel