swaybar: allow null status_command

Sway sets a default status_command which runs date every second. This
patch removes this behaviour so the user can have a NULL status bar if
desired.

I had to swap swaybar's event_loop_poll and wl_display_flush so that it
would map the initial surface.

sway/config/bar.c

@@ -99,10 +99,6 @@ struct bar_config *default_bar_config(void) {
 	if (!(bar->bindings = create_list())) {
 		goto cleanup;
 	}
-	if (!(bar->status_command =
-			strdup("while date +'%Y-%m-%d %l:%M:%S %p'; do sleep 1; done"))) {
-		goto cleanup;
-	}
 	// set default colors
 	if (!(bar->colors.background = strndup("#000000ff", 9))) {
 		goto cleanup;

sway/ipc-json.c

@@ -514,8 +514,8 @@ json_object *ipc_json_describe_bar_config(struct bar_config *bar) {
 			json_object_new_string(bar->hidden_state));
 	json_object_object_add(json, "position",
 			json_object_new_string(bar->position));
-	json_object_object_add(json, "status_command",
+	json_object_object_add(json, "status_command", bar->status_command ?
-			json_object_new_string(bar->status_command));
+			json_object_new_string(bar->status_command) : NULL);
 	json_object_object_add(json, "font",
 			json_object_new_string((bar->font) ? bar->font : config->font));
 	if (bar->separator_symbol) {

swaybar/bar.c

@@ -572,8 +572,8 @@ void bar_run(struct swaybar *bar) {
 		add_event(bar->status->read_fd, POLLIN, status_in, bar);
 	}
 	while (1) {
-		event_loop_poll();
 		wl_display_flush(bar->display);
+		event_loop_poll();
 	}
 }