xdg-shell: send maximized if tiled isn't supported

wlroots doesn't do it automatically anymore.

sway/desktop/xdg_shell.c

@@ -169,12 +169,19 @@ static void set_tiled(struct sway_view *view, bool tiled) {
 	if (xdg_shell_view_from_view(view) == NULL) {
 		return;
 	}
-	enum wlr_edges edges = WLR_EDGE_NONE;
-	if (tiled) {
-		edges = WLR_EDGE_LEFT | WLR_EDGE_RIGHT | WLR_EDGE_TOP |
-				WLR_EDGE_BOTTOM;
+	if (wl_resource_get_version(view->wlr_xdg_toplevel->resource) >=
+			XDG_TOPLEVEL_STATE_TILED_LEFT_SINCE_VERSION) {
+		enum wlr_edges edges = WLR_EDGE_NONE;
+		if (tiled) {
+			edges = WLR_EDGE_LEFT | WLR_EDGE_RIGHT | WLR_EDGE_TOP |
+					WLR_EDGE_BOTTOM;
+		}
+		wlr_xdg_toplevel_set_tiled(view->wlr_xdg_toplevel, edges);
+	} else {
+		// The version is too low for the tiled state; configure as maximized instead
+		// to stop the client from drawing decorations outside of the toplevel geometry.
+		wlr_xdg_toplevel_set_maximized(view->wlr_xdg_toplevel, tiled);
 	}
-	wlr_xdg_toplevel_set_tiled(view->wlr_xdg_toplevel, edges);
 }
 
 static void set_fullscreen(struct sway_view *view, bool fullscreen) {