fix unable to signout

oauth.go

@@ -210,12 +210,9 @@ func logoutHandler(c echo.Context) (err error) {
 			return echo.NewHTTPError(http.StatusInternalServerError)
 		}
 		request.Header.Add("User-Agent", USER_AGENT)
-		resp, err := http.DefaultClient.Do(request)
-		if err == nil && resp.StatusCode == http.StatusOK {
-			return c.NoContent(http.StatusOK)
-		}
-		c.Logger().Error(err)
-		return echo.NewHTTPError(http.StatusBadRequest)
+		http.DefaultClient.Do(request) // don't care even if revoking failed
+		writeSessionData(c, nil)       // to reset, write nil to user's session
+		return c.NoContent(http.StatusOK)
 	}
 
 	return echo.NewHTTPError(http.StatusUnauthorized, "login_required")

server.go

@@ -280,7 +280,11 @@ func writeSessionData(c echo.Context, data *SessionData) error {
 		return err
 	}
 
-	sess.Values[SESSION_DATASTORE_NAME] = data
+	if data == nil {
+		sess.Values[SESSION_DATASTORE_NAME] = ""
+	} else {
+		sess.Values[SESSION_DATASTORE_NAME] = data
+	}
 
 	return sess.Save(c.Request(), c.Response())
 }