[PATCH weston v3] compositor: reset surface's resource field on resource destruction

[Kristian Høgsberg]

On Fri, Sep 13, 2013 at 9:54 AM, Jason Ekstrand <jason at jlekstrand.net> wrote:
> Perhaps a better long-term solution would be to have the pointer register a
> destroy listener on the surface's resource and use that to null out the
> focus.  Then we wouldn't have to worry about specifically flagging this
> strange intermediate state.

Yes, that's the real problem and I think we should just fix that.
That's going to conflict/intersect with the multi-resource patches
from Rob though, so I think we should wait for that to land first.

Kristian

> --Jason Ekstrand
>
> On Sep 13, 2013 9:36 AM, "Giulio Camuffo" <giuliocamuffo at gmail.com> wrote:
>>
>> with the surface ref-count feature a surface may live on after its
>> resource was destroyed. set it to NULL in that case, so that code
>> like find_resource_for_surface() in input.c will act accordingly.
>> Moreover, we don't send the wl_pointer/keyboard_leave events if the
>> surface has a NULL resource.
>> ---
>>
>> Also fixed the silly write after free.
>>
>>  src/compositor.c |  4 ++++
>>  src/input.c      | 16 ++++++++++------
>>  2 files changed, 14 insertions(+), 6 deletions(-)
>>
>> diff --git a/src/compositor.c b/src/compositor.c
>> index 67ac64e..a1c01fb 100644
>> --- a/src/compositor.c
>> +++ b/src/compositor.c
>> @@ -1069,8 +1069,12 @@ static void
>>  destroy_surface(struct wl_resource *resource)
>>  {
>>         struct weston_surface *surface =
>> wl_resource_get_user_data(resource);
>> +       int destroyed = surface->ref_count <= 1;
>>
>>         weston_surface_destroy(surface);
>> +       if (!destroyed) {
>> +               surface->resource = NULL;
>> +       }
>>  }
>>
>>  static void
>> diff --git a/src/input.c b/src/input.c
>> index 9c30460..d6a4740 100644
>> --- a/src/input.c
>> +++ b/src/input.c
>> @@ -425,9 +425,11 @@ weston_pointer_set_focus(struct weston_pointer
>> *pointer,
>>
>>         resource = pointer->focus_resource;
>>         if (resource && pointer->focus != surface) {
>> -               serial = wl_display_next_serial(display);
>> -               wl_pointer_send_leave(resource, serial,
>> -                                     pointer->focus->resource);
>> +               if (pointer->focus->resource) {
>> +                       serial = wl_display_next_serial(display);
>> +                       wl_pointer_send_leave(resource, serial,
>> +                                               pointer->focus->resource);
>> +               }
>>                 wl_list_remove(&pointer->focus_listener.link);
>>         }
>>
>> @@ -471,9 +473,11 @@ weston_keyboard_set_focus(struct weston_keyboard
>> *keyboard,
>>
>>         if (keyboard->focus_resource && keyboard->focus != surface) {
>>                 resource = keyboard->focus_resource;
>> -               serial = wl_display_next_serial(display);
>> -               wl_keyboard_send_leave(resource, serial,
>> -                                      keyboard->focus->resource);
>> +               if (keyboard->focus->resource) {
>> +                       serial = wl_display_next_serial(display);
>> +                       wl_keyboard_send_leave(resource, serial,
>> +
>> keyboard->focus->resource);
>> +               }
>>                 wl_list_remove(&keyboard->focus_listener.link);
>>         }
>>
>> --
>> 1.8.4
>>
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>> wayland-devel at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/wayland-devel
>
>
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