Merge pull request #885 from emersion/remove-surface-subsurface

Remove wlr_surface::subsurface, add wlr_subcompositor

10 files changed, 162 insertions, 131 deletions

diff --git a/include/wlr/types/wlr_compositor.h b/include/wlr/types/wlr_compositor.h
index 922d7c0f..816ff713 100644
--- a/include/wlr/types/wlr_compositor.h
+++ b/include/wlr/types/wlr_compositor.h
@@ -6,12 +6,19 @@
 
 struct wlr_surface;
 
+struct wlr_subcompositor {
+	struct wl_global *wl_global;
+	struct wl_list wl_resources;
+};
+
 struct wlr_compositor {
 	struct wl_global *wl_global;
 	struct wl_list wl_resources;
 	struct wlr_renderer *renderer;
 	struct wl_list surfaces;
 
+	struct wlr_subcompositor subcompositor;
+
 	struct wl_listener display_destroy;
 
 	struct {
diff --git a/include/wlr/types/wlr_surface.h b/include/wlr/types/wlr_surface.h
index 62f03e37..35d47926 100644
--- a/include/wlr/types/wlr_surface.h
+++ b/include/wlr/types/wlr_surface.h
@@ -56,7 +56,8 @@ struct wlr_subsurface {
 	struct wl_list parent_link;
 	struct wl_list parent_pending_link;
 
-	struct wl_listener parent_destroy_listener;
+	struct wl_listener surface_destroy;
+	struct wl_listener parent_destroy;
 
 	struct {
 		struct wl_signal destroy;
@@ -87,9 +88,7 @@ struct wlr_surface {
 	void (*role_committed)(struct wlr_surface *surface, void *role_data);
 	void *role_data;
 
-	// subsurface properties
-	struct wlr_subsurface *subsurface;
-	struct wl_list subsurface_list; // wlr_subsurface::parent_link
+	struct wl_list subsurfaces; // wlr_subsurface::parent_link
 
 	// wlr_subsurface::parent_pending_link
 	struct wl_list subsurface_pending_list;
diff --git a/rootston/desktop.c b/rootston/desktop.c
index 4edcb5e3..6ddf56b8 100644
--- a/rootston/desktop.c
+++ b/rootston/desktop.c
@@ -459,7 +459,7 @@ void view_map(struct roots_view *view, struct wlr_surface *surface) {
 	view->wlr_surface = surface;
 
 	struct wlr_subsurface *subsurface;
-	wl_list_for_each(subsurface, &view->wlr_surface->subsurface_list,
+	wl_list_for_each(subsurface, &view->wlr_surface->subsurfaces,
 			parent_link) {
 		subsurface_create(view, subsurface);
 	}
diff --git a/rootston/output.c b/rootston/output.c
index 75bbd928..791b2819 100644
--- a/rootston/output.c
+++ b/rootston/output.c
@@ -318,7 +318,7 @@ static void render_view(struct roots_view *view, struct render_data *data) {
 }
 
 static bool has_standalone_surface(struct roots_view *view) {
-	if (!wl_list_empty(&view->wlr_surface->subsurface_list)) {
+	if (!wl_list_empty(&view->wlr_surface->subsurfaces)) {
 		return false;
 	}
 
diff --git a/types/wlr_compositor.c b/types/wlr_compositor.c
index 2f9d12c9..57f3bd91 100644
--- a/types/wlr_compositor.c
+++ b/types/wlr_compositor.c
@@ -10,7 +10,8 @@
 static const char *subsurface_role = "wl_subsurface";
 
 bool wlr_surface_is_subsurface(struct wlr_surface *surface) {
-	return strcmp(surface->role, subsurface_role) == 0;
+	return surface->role != NULL &&
+		strcmp(surface->role, subsurface_role) == 0;
 }
 
 struct wlr_subsurface *wlr_subsurface_from_surface(
@@ -19,9 +20,96 @@ struct wlr_subsurface *wlr_subsurface_from_surface(
 	return (struct wlr_subsurface *)surface->role_data;
 }
 
+static void subcompositor_handle_destroy(struct wl_client *client,
+		struct wl_resource *resource) {
+	wl_resource_destroy(resource);
+}
+
+static void subcompositor_handle_get_subsurface(struct wl_client *client,
+		struct wl_resource *resource, uint32_t id,
+		struct wl_resource *surface_resource,
+		struct wl_resource *parent_resource) {
+	struct wlr_surface *surface = wlr_surface_from_resource(surface_resource);
+	struct wlr_surface *parent = wlr_surface_from_resource(parent_resource);
+
+	static const char msg[] = "get_subsurface: wl_subsurface@";
+
+	if (surface == parent) {
+		wl_resource_post_error(resource,
+			WL_SUBCOMPOSITOR_ERROR_BAD_SURFACE,
+			"%s%d: wl_surface@%d cannot be its own parent",
+			msg, id, wl_resource_get_id(surface_resource));
+		return;
+	}
+
+	if (wlr_surface_is_subsurface(surface)) {
+		wl_resource_post_error(resource,
+			WL_SUBCOMPOSITOR_ERROR_BAD_SURFACE,
+			"%s%d: wl_surface@%d is already a sub-surface",
+			msg, id, wl_resource_get_id(surface_resource));
+		return;
+	}
+
+	if (wlr_surface_get_root_surface(parent) == surface) {
+		wl_resource_post_error(resource,
+			WL_SUBCOMPOSITOR_ERROR_BAD_SURFACE,
+			"%s%d: wl_surface@%d is an ancestor of parent",
+			msg, id, wl_resource_get_id(surface_resource));
+		return;
+	}
+
+	if (wlr_surface_set_role(surface, subsurface_role, resource,
+				WL_SUBCOMPOSITOR_ERROR_BAD_SURFACE) < 0) {
+		return;
+	}
+
+	wlr_surface_make_subsurface(surface, parent, id);
+}
+
+static const struct wl_subcompositor_interface subcompositor_interface = {
+	.destroy = subcompositor_handle_destroy,
+	.get_subsurface = subcompositor_handle_get_subsurface,
+};
+
+static void subcompositor_bind(struct wl_client *client, void *data,
+		uint32_t version, uint32_t id) {
+	struct wlr_subcompositor *subcompositor = data;
+	struct wl_resource *resource =
+		wl_resource_create(client, &wl_subcompositor_interface, 1, id);
+	if (resource == NULL) {
+		wl_client_post_no_memory(client);
+		return;
+	}
+	wl_resource_set_implementation(resource, &subcompositor_interface,
+		subcompositor, NULL);
+	wl_list_insert(&subcompositor->wl_resources, wl_resource_get_link(resource));
+}
+
+static void subcompositor_init(struct wlr_subcompositor *subcompositor,
+		struct wl_display *display) {
+	subcompositor->wl_global = wl_global_create(display,
+		&wl_subcompositor_interface, 1, subcompositor, subcompositor_bind);
+	if (subcompositor->wl_global == NULL) {
+		wlr_log_errno(L_ERROR, "Could not allocate subcompositor global");
+		return;
+	}
+	wl_list_init(&subcompositor->wl_resources);
+}
+
+static void subcompositor_finish(struct wlr_subcompositor *subcompositor) {
+	wl_global_destroy(subcompositor->wl_global);
+}
+
+
+
+
+
+
+
 static const struct wl_compositor_interface wl_compositor_impl;
 
-static struct wlr_compositor *compositor_from_resource(struct wl_resource *resource) {
+static struct wlr_compositor *compositor_from_resource(
+		struct wl_resource *resource) {
 	assert(wl_resource_instance_of(resource, &wl_compositor_interface,
 		&wl_compositor_impl));
 	return wl_resource_get_user_data(resource);
@@ -86,16 +174,15 @@ static void wl_compositor_bind(struct wl_client *wl_client, void *data,
 	struct wlr_compositor *compositor = data;
 	assert(wl_client && compositor);
 
-	struct wl_resource *wl_resource =
+	struct wl_resource *resource =
 		wl_resource_create(wl_client, &wl_compositor_interface, version, id);
-	if (wl_resource == NULL) {
+	if (resource == NULL) {
 		wl_client_post_no_memory(wl_client);
 		return;
 	}
-	wl_resource_set_implementation(wl_resource, &wl_compositor_impl,
+	wl_resource_set_implementation(resource, &wl_compositor_impl,
 		compositor, wl_compositor_destroy);
-	wl_list_insert(&compositor->wl_resources,
-		wl_resource_get_link(wl_resource));
+	wl_list_insert(&compositor->wl_resources, wl_resource_get_link(resource));
 }
 
 void wlr_compositor_destroy(struct wlr_compositor *compositor) {
@@ -103,82 +190,12 @@ void wlr_compositor_destroy(struct wlr_compositor *compositor) {
 		return;
 	}
 	wlr_signal_emit_safe(&compositor->events.destroy, compositor);
+	subcompositor_finish(&compositor->subcompositor);
 	wl_list_remove(&compositor->display_destroy.link);
 	wl_global_destroy(compositor->wl_global);
 	free(compositor);
 }
 
-static void subcompositor_destroy(struct wl_client *client,
-		struct wl_resource *resource) {
-	wl_resource_destroy(resource);
-}
-
-static void subcompositor_get_subsurface(struct wl_client *client,
-		struct wl_resource *resource, uint32_t id,
-		struct wl_resource *surface_resource,
-		struct wl_resource *parent_resource) {
-	struct wlr_surface *surface = wlr_surface_from_resource(surface_resource);
-	struct wlr_surface *parent = wlr_surface_from_resource(parent_resource);
-
-	static const char msg[] = "get_subsurface: wl_subsurface@";
-
-	if (surface == parent) {
-		wl_resource_post_error(resource,
-			WL_SUBCOMPOSITOR_ERROR_BAD_SURFACE,
-			"%s%d: wl_surface@%d cannot be its own parent",
-			msg, id, wl_resource_get_id(surface_resource));
-		return;
-	}
-
-	if (surface->subsurface) {
-		wl_resource_post_error(resource,
-			WL_SUBCOMPOSITOR_ERROR_BAD_SURFACE,
-			"%s%d: wl_surface@%d is already a sub-surface",
-			msg, id, wl_resource_get_id(surface_resource));
-		return;
-	}
-
-	if (wlr_surface_get_root_surface(parent) == surface) {
-		wl_resource_post_error(resource,
-			WL_SUBCOMPOSITOR_ERROR_BAD_SURFACE,
-			"%s%d: wl_surface@%d is an ancestor of parent",
-			msg, id, wl_resource_get_id(surface_resource));
-		return;
-	}
-
-	if (wlr_surface_set_role(surface, subsurface_role, resource,
-				WL_SUBCOMPOSITOR_ERROR_BAD_SURFACE) < 0) {
-		return;
-	}
-
-	wlr_surface_make_subsurface(surface, parent, id);
-	if (!surface->subsurface) {
-		wl_resource_post_no_memory(resource);
-		return;
-	}
-
-	surface->role_data = surface->subsurface;
-}
-
-
-static const struct wl_subcompositor_interface subcompositor_interface = {
-	.destroy = subcompositor_destroy,
-	.get_subsurface = subcompositor_get_subsurface,
-};
-
-static void subcompositor_bind(struct wl_client *client, void *data,
-		uint32_t version, uint32_t id) {
-	struct wlr_compositor *compositor = data;
-	struct wl_resource *resource =
-		wl_resource_create(client, &wl_subcompositor_interface, 1, id);
-	if (resource == NULL) {
-		wl_client_post_no_memory(client);
-		return;
-	}
-	wl_resource_set_implementation(resource, &subcompositor_interface,
-		compositor, NULL);
-}
-
 static void handle_display_destroy(struct wl_listener *listener, void *data) {
 	struct wlr_compositor *compositor =
 		wl_container_of(listener, compositor, display_destroy);
@@ -204,14 +221,13 @@ struct wlr_compositor *wlr_compositor_create(struct wl_display *display,
 	compositor->wl_global = compositor_global;
 	compositor->renderer = renderer;
 
-	wl_global_create(display, &wl_subcompositor_interface, 1, compositor,
-		subcompositor_bind);
-
 	wl_list_init(&compositor->wl_resources);
 	wl_list_init(&compositor->surfaces);
 	wl_signal_init(&compositor->events.new_surface);
 	wl_signal_init(&compositor->events.destroy);
 
+	subcompositor_init(&compositor->subcompositor, display);
+
 	compositor->display_destroy.notify = handle_display_destroy;
 	wl_display_add_destroy_listener(display, &compositor->display_destroy);
 
diff --git a/types/wlr_surface.c b/types/wlr_surface.c
index 320e2421..9c0324a0 100644
--- a/types/wlr_surface.c
+++ b/types/wlr_surface.c
@@ -3,6 +3,7 @@
 #include <wayland-server.h>
 #include <wlr/render/egl.h>
 #include <wlr/render/interface.h>
+#include <wlr/types/wlr_compositor.h>
 #include <wlr/types/wlr_matrix.h>
 #include <wlr/types/wlr_region.h>
 #include <wlr/types/wlr_surface.h>
@@ -129,8 +130,7 @@ static void surface_set_opaque_region(struct wl_client *client,
 }
 
 static void surface_set_input_region(struct wl_client *client,
-		struct wl_resource *resource,
-		struct wl_resource *region_resource) {
+		struct wl_resource *resource, struct wl_resource *region_resource) {
 	struct wlr_surface *surface = wlr_surface_from_resource(resource);
 	surface->pending->invalid |= WLR_SURFACE_INVALID_INPUT_REGION;
 	if (region_resource) {
@@ -326,7 +326,7 @@ static void wlr_surface_damage_subsurfaces(struct wlr_subsurface *subsurface) {
 	subsurface->reordered = false;
 
 	struct wlr_subsurface *child;
-	wl_list_for_each(child, &subsurface->surface->subsurface_list, parent_link) {
+	wl_list_for_each(child, &subsurface->surface->subsurfaces, parent_link) {
 		wlr_surface_damage_subsurfaces(child);
 	}
 }
@@ -418,7 +418,7 @@ static void wlr_surface_commit_pending(struct wlr_surface *surface) {
 	wl_list_for_each_reverse(subsurface, &surface->subsurface_pending_list,
 			parent_pending_link) {
 		wl_list_remove(&subsurface->parent_link);
-		wl_list_insert(&surface->subsurface_list, &subsurface->parent_link);
+		wl_list_insert(&surface->subsurfaces, &subsurface->parent_link);
 
 		if (subsurface->reordered) {
 			// TODO: damage all the subsurfaces
@@ -438,7 +438,7 @@ static void wlr_surface_commit_pending(struct wlr_surface *surface) {
 }
 
 static bool wlr_subsurface_is_synchronized(struct wlr_subsurface *subsurface) {
-	while (subsurface) {
+	while (1) {
 		if (subsurface->synchronized) {
 			return true;
 		}
@@ -447,7 +447,10 @@ static bool wlr_subsurface_is_synchronized(struct wlr_subsurface *subsurface) {
 			return false;
 		}
 
-		subsurface = subsurface->parent->subsurface;
+		if (!wlr_surface_is_subsurface(subsurface->parent)) {
+			break;
+		}
+		subsurface = wlr_subsurface_from_surface(subsurface->parent);
 	}
 
 	return false;
@@ -468,7 +471,7 @@ static void wlr_subsurface_parent_commit(struct wlr_subsurface *subsurface,
 		}
 
 		struct wlr_subsurface *tmp;
-		wl_list_for_each(tmp, &surface->subsurface_list, parent_link) {
+		wl_list_for_each(tmp, &surface->subsurfaces, parent_link) {
 			wlr_subsurface_parent_commit(tmp, true);
 		}
 	}
@@ -491,19 +494,19 @@ static void wlr_subsurface_commit(struct wlr_subsurface *subsurface) {
 		}
 
 		struct wlr_subsurface *tmp;
-		wl_list_for_each(tmp, &surface->subsurface_list, parent_link) {
+		wl_list_for_each(tmp, &surface->subsurfaces, parent_link) {
 			wlr_subsurface_parent_commit(tmp, false);
 		}
 	}
-
 }
 
 static void surface_commit(struct wl_client *client,
 		struct wl_resource *resource) {
 	struct wlr_surface *surface = wlr_surface_from_resource(resource);
-	struct wlr_subsurface *subsurface = surface->subsurface;
 
-	if (subsurface) {
+	if (wlr_surface_is_subsurface(surface)) {
+		struct wlr_subsurface *subsurface =
+			wlr_subsurface_from_surface(surface);
 		wlr_subsurface_commit(subsurface);
 		return;
 	}
@@ -511,7 +514,7 @@ static void surface_commit(struct wl_client *client,
 	wlr_surface_commit_pending(surface);
 
 	struct wlr_subsurface *tmp;
-	wl_list_for_each(tmp, &surface->subsurface_list, parent_link) {
+	wl_list_for_each(tmp, &surface->subsurfaces, parent_link) {
 		wlr_subsurface_parent_commit(tmp, false);
 	}
 }
@@ -603,28 +606,26 @@ static void wlr_surface_state_destroy(struct wlr_surface_state *state) {
 void wlr_subsurface_destroy(struct wlr_subsurface *subsurface) {
 	wlr_signal_emit_safe(&subsurface->events.destroy, subsurface);
 
+	wl_list_remove(&subsurface->surface_destroy.link);
 	wlr_surface_state_destroy(subsurface->cached);
 
 	if (subsurface->parent) {
 		wl_list_remove(&subsurface->parent_link);
 		wl_list_remove(&subsurface->parent_pending_link);
-		wl_list_remove(&subsurface->parent_destroy_listener.link);
+		wl_list_remove(&subsurface->parent_destroy.link);
 	}
 
 	wl_resource_set_user_data(subsurface->resource, NULL);
 	if (subsurface->surface) {
-		subsurface->surface->subsurface = NULL;
+		subsurface->surface->role_data = NULL;
 	}
 	free(subsurface);
 }
 
 static void destroy_surface(struct wl_resource *resource) {
 	struct wlr_surface *surface = wlr_surface_from_resource(resource);
-	wlr_signal_emit_safe(&surface->events.destroy, surface);
 
-	if (surface->subsurface) {
-		wlr_subsurface_destroy(surface->subsurface);
-	}
+	wlr_signal_emit_safe(&surface->events.destroy, surface);
 
 	wlr_texture_destroy(surface->texture);
 	wlr_surface_state_destroy(surface->pending);
@@ -650,7 +651,7 @@ struct wlr_surface *wlr_surface_create(struct wl_resource *res,
 	wl_signal_init(&surface->events.commit);
 	wl_signal_init(&surface->events.destroy);
 	wl_signal_init(&surface->events.new_subsurface);
-	wl_list_init(&surface->subsurface_list);
+	wl_list_init(&surface->subsurfaces);
 	wl_list_init(&surface->subsurface_pending_list);
 	wl_resource_set_implementation(res, &surface_interface,
 		surface, destroy_surface);
@@ -720,7 +721,7 @@ static struct wlr_subsurface *subsurface_find_sibling(
 	struct wlr_surface *parent = subsurface->parent;
 
 	struct wlr_subsurface *sibling;
-	wl_list_for_each(sibling, &parent->subsurface_list, parent_link) {
+	wl_list_for_each(sibling, &parent->subsurfaces, parent_link) {
 		if (sibling->surface == surface && sibling != subsurface) {
 			return sibling;
 		}
@@ -812,17 +813,23 @@ static const struct wl_subsurface_interface subsurface_implementation = {
 static void subsurface_handle_parent_destroy(struct wl_listener *listener,
 		void *data) {
 	struct wlr_subsurface *subsurface =
-		wl_container_of(listener, subsurface, parent_destroy_listener);
+		wl_container_of(listener, subsurface, parent_destroy);
 	wl_list_remove(&subsurface->parent_link);
 	wl_list_remove(&subsurface->parent_pending_link);
-	wl_list_remove(&subsurface->parent_destroy_listener.link);
+	wl_list_remove(&subsurface->parent_destroy.link);
 	subsurface->parent = NULL;
 }
 
+static void subsurface_handle_surface_destroy(struct wl_listener *listener,
+		void *data) {
+	struct wlr_subsurface *subsurface =
+		wl_container_of(listener, subsurface, surface_destroy);
+	wlr_subsurface_destroy(subsurface);
+}
+
 void wlr_surface_make_subsurface(struct wlr_surface *surface,
 		struct wlr_surface *parent, uint32_t id) {
 	struct wl_client *client = wl_resource_get_client(surface->resource);
-	assert(surface->subsurface == NULL);
 
 	struct wlr_subsurface *subsurface =
 		calloc(1, sizeof(struct wlr_subsurface));
@@ -839,14 +846,14 @@ void wlr_surface_make_subsurface(struct wlr_surface *surface,
 	subsurface->synchronized = true;
 	subsurface->surface = surface;
 	wl_signal_init(&subsurface->events.destroy);
+	wl_signal_add(&surface->events.destroy, &subsurface->surface_destroy);
+	subsurface->surface_destroy.notify = subsurface_handle_surface_destroy;
 
 	// link parent
 	subsurface->parent = parent;
-	wl_signal_add(&parent->events.destroy,
-		&subsurface->parent_destroy_listener);
-	subsurface->parent_destroy_listener.notify =
-		subsurface_handle_parent_destroy;
-	wl_list_insert(&parent->subsurface_list, &subsurface->parent_link);
+	wl_signal_add(&parent->events.destroy, &subsurface->parent_destroy);
+	subsurface->parent_destroy.notify = subsurface_handle_parent_destroy;
+	wl_list_insert(&parent->subsurfaces, &subsurface->parent_link);
 	wl_list_insert(&parent->subsurface_pending_list,
 		&subsurface->parent_pending_link);
 
@@ -863,21 +870,19 @@ void wlr_surface_make_subsurface(struct wlr_surface *surface,
 		&subsurface_implementation, subsurface,
 		subsurface_resource_destroy);
 
-	surface->subsurface = subsurface;
+	surface->role_data = subsurface;
 
 	wlr_signal_emit_safe(&parent->events.new_subsurface, subsurface);
 }
 
 
 struct wlr_surface *wlr_surface_get_root_surface(struct wlr_surface *surface) {
-	while (surface != NULL) {
-		struct wlr_subsurface *sub = surface->subsurface;
-		if (sub == NULL) {
-			return surface;
-		}
-		surface = sub->parent;
+	while (wlr_surface_is_subsurface(surface)) {
+		struct wlr_subsurface *subsurface =
+			wlr_subsurface_from_surface(surface);
+		surface = subsurface->surface;
 	}
-	return NULL;
+	return surface;
 }
 
 bool wlr_surface_point_accepts_input(struct wlr_surface *surface,
@@ -890,7 +895,7 @@ bool wlr_surface_point_accepts_input(struct wlr_surface *surface,
 struct wlr_surface *wlr_surface_surface_at(struct wlr_surface *surface,
 		double sx, double sy, double *sub_x, double *sub_y) {
 	struct wlr_subsurface *subsurface;
-	wl_list_for_each(subsurface, &surface->subsurface_list, parent_link) {
+	wl_list_for_each(subsurface, &surface->subsurfaces, parent_link) {
 		double _sub_x = subsurface->surface->current->subsurface_position.x;
 		double _sub_y = subsurface->surface->current->subsurface_position.y;
 		struct wlr_surface *sub = wlr_surface_surface_at(subsurface->surface,
@@ -957,7 +962,7 @@ static void surface_for_each_surface(struct wlr_surface *surface, int x, int y,
 	iterator(surface, x, y, user_data);
 
 	struct wlr_subsurface *subsurface;
-	wl_list_for_each(subsurface, &surface->subsurface_list, parent_link) {
+	wl_list_for_each(subsurface, &surface->subsurfaces, parent_link) {
 		struct wlr_surface_state *state = subsurface->surface->current;
 		int sx = state->subsurface_position.x;
 		int sy = state->subsurface_position.y;
diff --git a/types/wlr_wl_shell.c b/types/wlr_wl_shell.c
index 45a80221..5e4c24e7 100644
--- a/types/wlr_wl_shell.c
+++ b/types/wlr_wl_shell.c
@@ -13,7 +13,8 @@
 static const char *wlr_wl_shell_surface_role = "wl-shell-surface";
 
 bool wlr_surface_is_wl_shell_surface(struct wlr_surface *surface) {
-	return strcmp(surface->role, wlr_wl_shell_surface_role) == 0;
+	return surface->role != NULL &&
+		strcmp(surface->role, wlr_wl_shell_surface_role) == 0;
 }
 
 struct wlr_wl_surface *wlr_wl_shell_surface_from_wlr_surface(
diff --git a/types/wlr_xdg_shell.c b/types/wlr_xdg_shell.c
index 1aa964a6..8d424f3b 100644
--- a/types/wlr_xdg_shell.c
+++ b/types/wlr_xdg_shell.c
@@ -17,8 +17,9 @@ static const char *wlr_desktop_xdg_toplevel_role = "xdg_toplevel";
 static const char *wlr_desktop_xdg_popup_role = "xdg_popup";
 
 bool wlr_surface_is_xdg_surface(struct wlr_surface *surface) {
-	return strcmp(surface->role, wlr_desktop_xdg_toplevel_role) == 0 ||
-		strcmp(surface->role, wlr_desktop_xdg_popup_role) == 0;
+	return surface->role != NULL &&
+		(strcmp(surface->role, wlr_desktop_xdg_toplevel_role) == 0 ||
+		strcmp(surface->role, wlr_desktop_xdg_popup_role) == 0);
 }
 
 struct wlr_xdg_surface *wlr_xdg_surface_from_wlr_surface(
diff --git a/types/wlr_xdg_shell_v6.c b/types/wlr_xdg_shell_v6.c
index 3bd845d3..22b387f1 100644
--- a/types/wlr_xdg_shell_v6.c
+++ b/types/wlr_xdg_shell_v6.c
@@ -17,8 +17,9 @@ static const char *wlr_desktop_xdg_toplevel_role = "xdg_toplevel_v6";
 static const char *wlr_desktop_xdg_popup_role = "xdg_popup_v6";
 
 bool wlr_surface_is_xdg_surface_v6(struct wlr_surface *surface) {
-	return strcmp(surface->role, wlr_desktop_xdg_toplevel_role) == 0 ||
-		strcmp(surface->role, wlr_desktop_xdg_popup_role) == 0;
+	return surface->role != NULL &&
+		(strcmp(surface->role, wlr_desktop_xdg_toplevel_role) == 0 ||
+		strcmp(surface->role, wlr_desktop_xdg_popup_role) == 0);
 }
 
 struct wlr_xdg_surface_v6 *wlr_xdg_surface_v6_from_wlr_surface(
diff --git a/xwayland/xwm.c b/xwayland/xwm.c
index 77dc0797..599006ae 100644
--- a/xwayland/xwm.c
+++ b/xwayland/xwm.c
@@ -80,7 +80,8 @@ const char *atom_map[ATOM_LAST] = {
 const char *wlr_xwayland_surface_role = "wlr_xwayland_surface";
 
 bool wlr_surface_is_xwayland_surface(struct wlr_surface *surface) {
-	return strcmp(surface->role, wlr_xwayland_surface_role) == 0;
+	return surface->role != NULL &&
+		strcmp(surface->role, wlr_xwayland_surface_role) == 0;
 }
 
 struct wlr_xwayland_surface *wlr_xwayland_surface_from_wlr_surface(