[PATCH weston 1/8] libweston: Make weston_pointer destruction safe

[Alexandros Frantzis]

Properly clean up all sub-objects (e.g., weston_pointer_client objects)
when a weston_pointer object is destroyed. The clean-up ensures that the
server is able to safely handle client requests to any associated
pointer resources, which, as a consenquence of a weston_pointer
destruction, have now become inert.

The clean-up involves, among other things, unsetting the destroyed
weston_pointer object from the user data of pointer resources, and
handling this NULL user data case where required.

Signed-off-by: Alexandros Frantzis <alexandros.frantzis at collabora.com>
---
 libweston/input.c | 41 ++++++++++++++++++++++++++++++++++++-----
 1 file changed, 36 insertions(+), 5 deletions(-)

diff --git a/libweston/input.c b/libweston/input.c
index 94a3423a..01f0d568 100644
--- a/libweston/input.c
+++ b/libweston/input.c
@@ -105,6 +105,19 @@ weston_pointer_client_create(struct wl_client *client)
 static void
 weston_pointer_client_destroy(struct weston_pointer_client *pointer_client)
 {
+	struct wl_resource *resource;
+
+	wl_resource_for_each(resource, &pointer_client->pointer_resources) {
+		wl_resource_set_user_data(resource, NULL);
+	}
+
+	wl_resource_for_each(resource,
+			     &pointer_client->relative_pointer_resources) {
+		wl_resource_set_user_data(resource, NULL);
+	}
+
+	wl_list_remove(&pointer_client->pointer_resources);
+	wl_list_remove(&pointer_client->relative_pointer_resources);
 	free(pointer_client);
 }
 
@@ -170,11 +183,14 @@ unbind_pointer_client_resource(struct wl_resource *resource)
 	struct wl_client *client = wl_resource_get_client(resource);
 	struct weston_pointer_client *pointer_client;
 
-	pointer_client = weston_pointer_get_pointer_client(pointer, client);
-	assert(pointer_client);
-
 	wl_list_remove(wl_resource_get_link(resource));
-	weston_pointer_cleanup_pointer_client(pointer, pointer_client);
+
+	if (pointer) {
+		pointer_client = weston_pointer_get_pointer_client(pointer,
+								   client);
+		assert(pointer_client);
+		weston_pointer_cleanup_pointer_client(pointer, pointer_client);
+	}
 }
 
 static void unbind_resource(struct wl_resource *resource)
@@ -1092,12 +1108,18 @@ weston_pointer_create(struct weston_seat *seat)
 WL_EXPORT void
 weston_pointer_destroy(struct weston_pointer *pointer)
 {
+	struct weston_pointer_client *pointer_client, *tmp;
+
 	wl_signal_emit(&pointer->destroy_signal, pointer);
 
 	if (pointer->sprite)
 		pointer_unmap_sprite(pointer);
 
-	/* XXX: What about pointer->resource_list? */
+	wl_list_for_each_safe(pointer_client, tmp, &pointer->pointer_clients,
+			      link) {
+		wl_list_remove(&pointer_client->link);
+		weston_pointer_client_destroy(pointer_client);
+	}
 
 	wl_list_remove(&pointer->focus_resource_listener.link);
 	wl_list_remove(&pointer->focus_view_listener.link);
@@ -2297,6 +2319,9 @@ pointer_set_cursor(struct wl_client *client, struct wl_resource *resource,
 	struct weston_pointer *pointer = wl_resource_get_user_data(resource);
 	struct weston_surface *surface = NULL;
 
+	if (!pointer)
+		return;
+
 	if (surface_resource)
 		surface = wl_resource_get_user_data(surface_resource);
 
@@ -3674,6 +3699,9 @@ pointer_constraints_lock_pointer(struct wl_client *client,
 	struct weston_region *region = region_resource ?
 		wl_resource_get_user_data(region_resource) : NULL;
 
+	if (!pointer)
+		return;
+
 	init_pointer_constraint(resource, id, surface, pointer, region, lifetime,
 				&zwp_locked_pointer_v1_interface,
 				&locked_pointer_interface,
@@ -4467,6 +4495,9 @@ pointer_constraints_confine_pointer(struct wl_client *client,
 	struct weston_region *region = region_resource ?
 		wl_resource_get_user_data(region_resource) : NULL;
 
+	if (!pointer)
+		return;
+
 	init_pointer_constraint(resource, id, surface, pointer, region, lifetime,
 				&zwp_confined_pointer_v1_interface,
 				&confined_pointer_interface,
-- 
2.14.1