lock: set LockedHint when locking with loginctl lock integration

- was previously read-only
fixes #2732

core/internal/server/loginctl/actions.go

@@ -46,6 +46,19 @@ func (m *Manager) Activate() error {
 	return nil
 }
 
+func (m *Manager) SetLockedHint(locked bool) error {
+	err := m.sessionObj.Call(dbusSessionInterface+".SetLockedHint", 0, locked).Err
+	if err != nil {
+		if refreshErr := m.refreshSessionBinding(); refreshErr == nil {
+			err = m.sessionObj.Call(dbusSessionInterface+".SetLockedHint", 0, locked).Err
+		}
+		if err != nil {
+			return fmt.Errorf("failed to set locked hint: %w", err)
+		}
+	}
+	return nil
+}
+
 func (m *Manager) SetIdleHint(idle bool) error {
 	err := m.sessionObj.Call(dbusSessionInterface+".SetIdleHint", 0, idle).Err
 	if err != nil {

core/internal/server/loginctl/handlers.go

@@ -21,6 +21,8 @@ func HandleRequest(conn net.Conn, req models.Request, manager *Manager) {
 		handleActivate(conn, req, manager)
 	case "loginctl.setIdleHint":
 		handleSetIdleHint(conn, req, manager)
+	case "loginctl.setLockedHint":
+		handleSetLockedHint(conn, req, manager)
 	case "loginctl.setLockBeforeSuspend":
 		handleSetLockBeforeSuspend(conn, req, manager)
 	case "loginctl.setSleepInhibitorEnabled":
@@ -78,6 +80,20 @@ func handleSetIdleHint(conn net.Conn, req models.Request, manager *Manager) {
 	models.Respond(conn, req.ID, models.SuccessResult{Success: true, Message: "idle hint set"})
 }
 
+func handleSetLockedHint(conn net.Conn, req models.Request, manager *Manager) {
+	locked, err := params.Bool(req.Params, "locked")
+	if err != nil {
+		models.RespondError(conn, req.ID, err.Error())
+		return
+	}
+
+	if err := manager.SetLockedHint(locked); err != nil {
+		models.RespondError(conn, req.ID, err.Error())
+		return
+	}
+	models.Respond(conn, req.ID, models.SuccessResult{Success: true, Message: "locked hint set"})
+}
+
 func handleSetLockBeforeSuspend(conn net.Conn, req models.Request, manager *Manager) {
 	enabled, err := params.Bool(req.Params, "enabled")
 	if err != nil {