[PATCH weston 4/5] compositor: fix crash when a drag surface is destroyed during the drag

[Kristian Hoegsberg]

On Thu, Mar 01, 2012 at 02:09:44PM +0200, Ander Conselvan de Oliveira wrote:
> This can happen for instance if the client that started the drag
> crashes. Weston would crash because of the invalid surface pointed by
> device->drag_surface.

Looks good, applied.
Kristian

> Fix this by reseting the drag surface to nil on a destroy listener.
> ---
>  src/compositor.c |   17 +++++++++++++++++
>  src/compositor.h |    1 +
>  2 files changed, 18 insertions(+), 0 deletions(-)
> 
> diff --git a/src/compositor.c b/src/compositor.c
> index 74c40da..4b607d0 100644
> --- a/src/compositor.c
> +++ b/src/compositor.c
> @@ -1850,6 +1850,18 @@ const static struct wl_input_device_interface input_device_interface = {
>  	input_device_attach,
>  };
>  
> +static void
> +handle_drag_surface_destroy(struct wl_listener *listener,
> +			    struct wl_resource *resource, uint32_t time)
> +{
> +	struct weston_input_device *device;
> +
> +	device = container_of(listener, struct weston_input_device,
> +			      drag_surface_destroy_listener);
> +
> +	device->drag_surface = NULL;
> +}
> +
>  static void unbind_input_device(struct wl_resource *resource)
>  {
>  	wl_list_remove(&resource->link);
> @@ -1886,6 +1898,8 @@ weston_input_device_init(struct weston_input_device *device,
>  	device->modifier_state = 0;
>  	device->num_tp = 0;
>  
> +	device->drag_surface_destroy_listener.func = handle_drag_surface_destroy;
> +
>  	wl_list_insert(ec->input_device_list.prev, &device->link);
>  }
>  
> @@ -1920,6 +1934,7 @@ weston_input_update_drag_surface(struct wl_input_device *input_device,
>  
>  	if (!input_device->drag_surface || surface_changed) {
>  		undef_region(&device->drag_surface->input);
> +		wl_list_remove(&device->drag_surface_destroy_listener.link);
>  		device->drag_surface = NULL;
>  		if (!surface_changed)
>  			return;
> @@ -1931,6 +1946,8 @@ weston_input_update_drag_surface(struct wl_input_device *input_device,
>  
>  		weston_surface_set_position(device->drag_surface,
>  					    input_device->x, input_device->y);
> +		wl_list_insert(device->drag_surface->surface.resource.destroy_listener_list.prev,
> +			       &device->drag_surface_destroy_listener.link);
>  	}
>  
>  	if (device->drag_surface->output == NULL &&
> diff --git a/src/compositor.h b/src/compositor.h
> index dd9cb20..ab881c5 100644
> --- a/src/compositor.h
> +++ b/src/compositor.h
> @@ -93,6 +93,7 @@ struct weston_input_device {
>  	struct weston_compositor *compositor;
>  	struct weston_surface *sprite;
>  	struct weston_surface *drag_surface;
> +	struct wl_listener drag_surface_destroy_listener;
>  	int32_t hotspot_x, hotspot_y;
>  	struct wl_list link;
>  	uint32_t modifier_state;
> -- 
> 1.7.4.1
> 
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