lib/dbus/Glue: use private connection

Avoid interfering with libraries also using the shared connection.

src/lib/dbus/Connection.cxx

@@ -42,6 +42,15 @@ ODBus::Connection::GetSystem()
 	return Connection(c);
 }
 
+ODBus::Connection
+ODBus::Connection::GetSystemPrivate()
+{
+	ODBus::Error error;
+	auto *c = dbus_bus_get_private(DBUS_BUS_SYSTEM, error);
+	error.CheckThrow("DBus connection error");
+	return Connection(c);
+}
+
 ODBus::Connection
 ODBus::Connection::Open(const char *address)
 {

src/lib/dbus/Connection.hxx

@@ -69,6 +69,7 @@ public:
 	}
 
 	static Connection GetSystem();
+	static Connection GetSystemPrivate();
 	static Connection Open(const char *address);
 
 	operator DBusConnection *() noexcept {
@@ -78,6 +79,10 @@ public:
 	operator bool() const noexcept {
 		return c != nullptr;
 	}
+
+	void Close() noexcept {
+		dbus_connection_close(c);
+	}
 };
 
 } /* namespace ODBus */

src/lib/dbus/Glue.cxx

@@ -25,7 +25,7 @@ namespace ODBus {
 void
 Glue::Connect()
 {
-	watch.SetConnection(Connection::GetSystem());
+	watch.SetConnection(Connection::GetSystemPrivate());
 
 	dbus_connection_set_exit_on_disconnect(GetConnection(), false);
 }
@@ -33,6 +33,8 @@ Glue::Connect()
 void
 Glue::Disconnect()
 {
+	GetConnection().Close();
+
 	watch.SetConnection(Connection());
 }