Don't trust SNI names, fixes #1274

If an item doesn't have a well-formed name, it will not be added to the
tray.

include/swaybar/tray/sni.h

@@ -28,6 +28,7 @@ void sni_icon_ref_free(struct sni_icon_ref *sni_ref);
 
 /**
  * Will return a new item and get its icon. (see warning below)
+ * May return `NULL` if `name` is not valid.
  */
 struct StatusNotifierItem *sni_create(const char *name);
 

swaybar/tray/sni.c

@@ -413,6 +413,12 @@ static void get_unique_name(struct StatusNotifierItem *item) {
 }
 
 struct StatusNotifierItem *sni_create(const char *name) {
+	// Make sure `name` is well formed
+	if (!dbus_validate_bus_name(name, NULL)) {
+		sway_log(L_INFO, "Name (%s) is not a bus name. We cannot create an item.", name);
+		return NULL;
+	}
+
 	struct StatusNotifierItem *item = malloc(sizeof(struct StatusNotifierItem));
 	item->name = strdup(name);
 	item->unique_name = NULL;

swaybar/tray/tray.c

@@ -90,10 +90,12 @@ static void get_items_reply(DBusPendingCall *pending, void *_data) {
 
 		struct StatusNotifierItem *item = sni_create(name);
 
+		if (item) {
 			sway_log(L_DEBUG, "Item registered with host: %s", name);
 			list_add(tray->items, item);
 			dirty = true;
 		}
+	}
 
 bail:
 	dbus_message_unref(reply);
@@ -141,9 +143,11 @@ static DBusHandlerResult signal_handler(DBusConnection *connection,
 		if (list_seq_find(tray->items, sni_str_cmp, name) == -1) {
 			struct StatusNotifierItem *item = sni_create(name);
 
+			if (item) {
 				list_add(tray->items, item);
 				dirty = true;
 			}
+		}
 
 		return DBUS_HANDLER_RESULT_HANDLED;
 	} else if (dbus_message_is_signal(message, "org.freedesktop.StatusNotifierWatcher",