xdg_shell: listen to fullscreen request on map

That event comes from the toplevel and not the surface, so would cause
a use-after-free on destroy if the toplevel got destroyed first:

==5454==ERROR: AddressSanitizer: heap-use-after-free on address 0x6110001ed198 at pc 0x000000472d10 bp 0x7ffc19070a80 sp 0x7ffc19070a70
WRITE of size 8 at 0x6110001ed198 thread T0
    #0 0x472d0f in wl_list_remove ../common/list.c:157
    #1 0x42e159 in handle_destroy ../sway/desktop/xdg_shell_v6.c:243
    #2 0x7fa9e5b28ce8 in wlr_signal_emit_safe ../util/signal.c:29
    #3 0x7fa9e5afd6b1 in destroy_xdg_surface_v6 ../types/xdg_shell_v6/wlr_xdg_surface_v6.c:101
    #4 0x7fa9e5d98025 in destroy_resource src/wayland-server.c:688
    #5 0x7fa9e5d98091 in wl_resource_destroy src/wayland-server.c:705
    #6 0x7fa9e27f103d in ffi_call_unix64 (/lib64/libffi.so.6+0x603d)
    #7 0x7fa9e27f09fe in ffi_call (/lib64/libffi.so.6+0x59fe)
    #8 0x7fa9e5d9bf2c  (/lib64/libwayland-server.so.0+0xbf2c)
    #9 0x7fa9e5d983de in wl_client_connection_data src/wayland-server.c:420
    #10 0x7fa9e5d99f01 in wl_event_loop_dispatch src/event-loop.c:641
    #11 0x7fa9e5d98601 in wl_display_run src/wayland-server.c:1260
    #12 0x40a2f4 in main ../sway/main.c:433
    #13 0x7fa9e527318a in __libc_start_main ../csu/libc-start.c:308
    #14 0x40b749 in _start (/opt/wayland/bin/sway+0x40b749)

0x6110001ed198 is located 152 bytes inside of 240-byte region [0x6110001ed100,0x6110001ed1f0)
freed by thread T0 here:
    #0 0x7fa9e7c89880 in __interceptor_free (/lib64/libasan.so.5+0xee880)
    #1 0x7fa9e5affce9 in destroy_xdg_toplevel_v6 ../types/xdg_shell_v6/wlr_xdg_toplevel_v6.c:23
    #2 0x7fa9e5d98025 in destroy_resource src/wayland-server.c:688

previously allocated by thread T0 here:
    #0 0x7fa9e7c89e50 in calloc (/lib64/libasan.so.5+0xeee50)
    #1 0x7fa9e5b00eea in create_xdg_toplevel_v6 ../types/xdg_shell_v6/wlr_xdg_toplevel_v6.c:427
    #2 0x7fa9e27f103d in ffi_call_unix64 (/lib64/libffi.so.6+0x603d)

The toplevel only notifies the compositor on destroy if it was mapped,
so only listen to events at map time.

1 files changed, 28 insertions, 28 deletions

diff --git a/sway/desktop/xdg_shell.c b/sway/desktop/xdg_shell.c
index 5b40d903..82db4076 100644
--- a/sway/desktop/xdg_shell.c
+++ b/sway/desktop/xdg_shell.c
@@ -203,6 +203,29 @@ static void handle_new_popup(struct wl_listener *listener, void *data) {
         popup_create(wlr_popup, &xdg_shell_view->view);
 }
 
+static void handle_request_fullscreen(struct wl_listener *listener, void *data) {
+        struct sway_xdg_shell_view *xdg_shell_view =
+                wl_container_of(listener, xdg_shell_view, request_fullscreen);
+        struct wlr_xdg_toplevel_set_fullscreen_event *e = data;
+        struct wlr_xdg_surface *xdg_surface =
+                xdg_shell_view->view.wlr_xdg_surface;
+        struct sway_view *view = &xdg_shell_view->view;
+
+        if (!sway_assert(xdg_surface->role == WLR_XDG_SURFACE_ROLE_TOPLEVEL,
+                                "xdg_shell requested fullscreen of surface with role %i",
+                                xdg_surface->role)) {
+                return;
+        }
+        if (!xdg_surface->mapped) {
+                return;
+        }
+
+        view_set_fullscreen(view, e->fullscreen);
+
+        struct sway_container *ws = container_parent(view->swayc, C_WORKSPACE);
+        arrange_and_commit(ws);
+}
+
 static void handle_unmap(struct wl_listener *listener, void *data) {
         struct sway_xdg_shell_view *xdg_shell_view =
                 wl_container_of(listener, xdg_shell_view, unmap);
@@ -216,6 +239,7 @@ static void handle_unmap(struct wl_listener *listener, void *data) {
 
         wl_list_remove(&xdg_shell_view->commit.link);
         wl_list_remove(&xdg_shell_view->new_popup.link);
+        wl_list_remove(&xdg_shell_view->request_fullscreen.link);
 }
 
 static void handle_map(struct wl_listener *listener, void *data) {
@@ -248,6 +272,10 @@ static void handle_map(struct wl_listener *listener, void *data) {
         xdg_shell_view->new_popup.notify = handle_new_popup;
         wl_signal_add(&xdg_surface->events.new_popup,
                 &xdg_shell_view->new_popup);
+
+        xdg_shell_view->request_fullscreen.notify = handle_request_fullscreen;
+        wl_signal_add(&xdg_surface->toplevel->events.request_fullscreen,
+                        &xdg_shell_view->request_fullscreen);
 }
 
 static void handle_destroy(struct wl_listener *listener, void *data) {
@@ -261,34 +289,10 @@ static void handle_destroy(struct wl_listener *listener, void *data) {
         wl_list_remove(&xdg_shell_view->destroy.link);
         wl_list_remove(&xdg_shell_view->map.link);
         wl_list_remove(&xdg_shell_view->unmap.link);
-        wl_list_remove(&xdg_shell_view->request_fullscreen.link);
         view->wlr_xdg_surface = NULL;
         view_destroy(view);
 }
 
-static void handle_request_fullscreen(struct wl_listener *listener, void *data) {
-        struct sway_xdg_shell_view *xdg_shell_view =
-                wl_container_of(listener, xdg_shell_view, request_fullscreen);
-        struct wlr_xdg_toplevel_set_fullscreen_event *e = data;
-        struct wlr_xdg_surface *xdg_surface =
-                xdg_shell_view->view.wlr_xdg_surface;
-        struct sway_view *view = &xdg_shell_view->view;
-
-        if (!sway_assert(xdg_surface->role == WLR_XDG_SURFACE_ROLE_TOPLEVEL,
-                                "xdg_shell requested fullscreen of surface with role %i",
-                                xdg_surface->role)) {
-                return;
-        }
-        if (!xdg_surface->mapped) {
-                return;
-        }
-
-        view_set_fullscreen(view, e->fullscreen);
-
-        struct sway_container *ws = container_parent(view->swayc, C_WORKSPACE);
-        arrange_and_commit(ws);
-}
-
 struct sway_view *view_from_wlr_xdg_surface(
                 struct wlr_xdg_surface *xdg_surface) {
         return xdg_surface->data;
@@ -329,9 +333,5 @@ void handle_xdg_shell_surface(struct wl_listener *listener, void *data) {
         xdg_shell_view->destroy.notify = handle_destroy;
         wl_signal_add(&xdg_surface->events.destroy, &xdg_shell_view->destroy);
 
-        xdg_shell_view->request_fullscreen.notify = handle_request_fullscreen;
-        wl_signal_add(&xdg_surface->toplevel->events.request_fullscreen,
-                        &xdg_shell_view->request_fullscreen);
-
         xdg_surface->data = xdg_shell_view;
 }