[PATCH weston] libweston-desktop: fix stale ping when a surface is destroyed

[Giulio Camuffo]

When sending a ping event to a surface using the wl_shell interface,
if that surface is destroyed before we receive the pong we will never
receive it, even if the client is actually responsive, since the
interface does not exist anymore. So when the surface if destroyed
pretend it's a pong and reset the ping state.
---
 libweston-desktop/client.c   | 14 ++++----------
 libweston-desktop/internal.h | 12 +++++++++++-
 libweston-desktop/surface.c  |  4 ++++
 3 files changed, 19 insertions(+), 11 deletions(-)

diff --git a/libweston-desktop/client.c b/libweston-desktop/client.c
index 29c3c98..ee8a2f8 100644
--- a/libweston-desktop/client.c
+++ b/libweston-desktop/client.c
@@ -31,16 +31,6 @@
 #include "libweston-desktop.h"
 #include "internal.h"
 
-struct weston_desktop_client {
-	struct weston_desktop *desktop;
-	struct wl_client *client;
-	struct wl_resource *resource;
-	struct wl_list surface_list;
-	uint32_t ping_serial;
-	struct wl_event_source *ping_timer;
-	struct wl_signal destroy_signal;
-};
-
 void
 weston_desktop_client_add_destroy_listener(struct weston_desktop_client *client,
 					   struct wl_listener *listener)
@@ -75,6 +65,8 @@ static int
 weston_desktop_client_ping_timeout(void *user_data)
 {
 	struct weston_desktop_client *client = user_data;
+	if (client->ping_serial == 0)
+		return 1;
 
 	weston_desktop_api_ping_timeout(client->desktop, client);
 	return 1;
@@ -192,6 +184,7 @@ weston_desktop_client_ping(struct weston_desktop_client *client)
 
 	client->ping_serial =
 		wl_display_next_serial(wl_client_get_display(client->client));
+	client->ping_surface = surface;
 	wl_event_source_timer_update(client->ping_timer, 10000);
 
 	implementation->ping(surface, client->ping_serial, implementation_data);
@@ -209,4 +202,5 @@ weston_desktop_client_pong(struct weston_desktop_client *client, uint32_t serial
 
 	wl_event_source_timer_update(client->ping_timer, 0);
 	client->ping_serial = 0;
+	client->ping_surface = NULL;
 }
diff --git a/libweston-desktop/internal.h b/libweston-desktop/internal.h
index a9c974b..7a4e6b2 100644
--- a/libweston-desktop/internal.h
+++ b/libweston-desktop/internal.h
@@ -27,7 +27,17 @@
 #include "compositor.h"
 
 struct weston_desktop_seat;
-struct weston_desktop_client;
+
+struct weston_desktop_client {
+	struct weston_desktop *desktop;
+	struct wl_client *client;
+	struct wl_resource *resource;
+	struct wl_list surface_list;
+	uint32_t ping_serial;
+	struct weston_desktop_surface *ping_surface;
+	struct wl_event_source *ping_timer;
+	struct wl_signal destroy_signal;
+};
 
 struct weston_compositor *
 weston_desktop_get_compositor(struct weston_desktop *desktop);
diff --git a/libweston-desktop/surface.c b/libweston-desktop/surface.c
index 2205107..e448280 100644
--- a/libweston-desktop/surface.c
+++ b/libweston-desktop/surface.c
@@ -127,6 +127,10 @@ weston_desktop_surface_destroy(struct weston_desktop_surface *surface)
 {
 	struct weston_desktop_view *view, *next_view;
 	struct weston_desktop_surface *child, *next_child;
+	struct weston_desktop_client *client = surface->client;
+
+	if (client->ping_surface == surface)
+		weston_desktop_client_pong(client, client->ping_serial);
 
 	wl_list_remove(&surface->surface_commit_listener.link);
 	wl_list_remove(&surface->surface_destroy_listener.link);
-- 
2.10.0