Redirect on changed user and org name (#11649)

* Add redirect for user

* Add redirect for orgs

* Add user redirect test

* Appease linter

* Add comment to DeleteUserRedirect function

* Fix locale changes

* Fix GetUserByParams

* Fix orgAssignment

* Remove debug logging

* Add redirect prompt

* Dont Export DeleteUserRedirect & only use it within a session

* Unexport newUserRedirect

* cleanup

* Fix & Dedub API code

* Format Template

* Add Migration & rm dublicat

* Refactor: unexport newRepoRedirect() & rm dedub del exec

* if this fails we'll need to re-rename the user directory

Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: zeripath <art27@cantab.net>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

models/user_redirect_test.go

@@ -0,0 +1,69 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package models
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestLookupUserRedirect(t *testing.T) {
+	assert.NoError(t, PrepareTestDatabase())
+
+	userID, err := LookupUserRedirect("olduser1")
+	assert.NoError(t, err)
+	assert.EqualValues(t, 1, userID)
+
+	_, err = LookupUserRedirect("doesnotexist")
+	assert.True(t, IsErrUserRedirectNotExist(err))
+}
+
+func TestNewUserRedirect(t *testing.T) {
+	// redirect to a completely new name
+	assert.NoError(t, PrepareTestDatabase())
+
+	user := AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
+	assert.NoError(t, newUserRedirect(x, user.ID, user.Name, "newusername"))
+
+	AssertExistsAndLoadBean(t, &UserRedirect{
+		LowerName:      user.LowerName,
+		RedirectUserID: user.ID,
+	})
+	AssertExistsAndLoadBean(t, &UserRedirect{
+		LowerName:      "olduser1",
+		RedirectUserID: user.ID,
+	})
+}
+
+func TestNewUserRedirect2(t *testing.T) {
+	// redirect to previously used name
+	assert.NoError(t, PrepareTestDatabase())
+
+	user := AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
+	assert.NoError(t, newUserRedirect(x, user.ID, user.Name, "olduser1"))
+
+	AssertExistsAndLoadBean(t, &UserRedirect{
+		LowerName:      user.LowerName,
+		RedirectUserID: user.ID,
+	})
+	AssertNotExistsBean(t, &UserRedirect{
+		LowerName:      "olduser1",
+		RedirectUserID: user.ID,
+	})
+}
+
+func TestNewUserRedirect3(t *testing.T) {
+	// redirect for a previously-unredirected user
+	assert.NoError(t, PrepareTestDatabase())
+
+	user := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	assert.NoError(t, newUserRedirect(x, user.ID, user.Name, "newusername"))
+
+	AssertExistsAndLoadBean(t, &UserRedirect{
+		LowerName:      user.LowerName,
+		RedirectUserID: user.ID,
+	})
+}