Add a simple way to rename branch like gh (#15870)

- Update default branch if needed
- Update protected branch if needed
- Update all not merged pull request base branch name
- Rename git branch
- Record this rename work and auto redirect for old branch on ui

Signed-off-by: a1012112796 <1012112796@qq.com>
Co-authored-by: delvh <dev.lh@web.de>

14 files changed, 357 insertions, 1 deletions

diff --git a/integrations/rename_branch_test.go b/integrations/rename_branch_test.go
new file mode 100644
index 0000000000..90c1f4d15f
--- /dev/null
+++ b/integrations/rename_branch_test.go
@@ -0,0 +1,44 @@
+// Copyright 2021 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 integrations
+
+import (
+	"net/http"
+	"testing"
+
+	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestRenameBranch(t *testing.T) {
+	// get branch setting page
+	session := loginUser(t, "user2")
+	req := NewRequest(t, "GET", "/user2/repo1/settings/branches")
+	resp := session.MakeRequest(t, req, http.StatusOK)
+	htmlDoc := NewHTMLParser(t, resp.Body)
+
+	postData := map[string]string{
+		"_csrf": htmlDoc.GetCSRF(),
+		"from":  "master",
+		"to":    "main",
+	}
+	req = NewRequestWithValues(t, "POST", "/user2/repo1/settings/rename_branch", postData)
+	session.MakeRequest(t, req, http.StatusFound)
+
+	// check new branch link
+	req = NewRequestWithValues(t, "GET", "/user2/repo1/src/branch/main/README.md", postData)
+	session.MakeRequest(t, req, http.StatusOK)
+
+	// check old branch link
+	req = NewRequestWithValues(t, "GET", "/user2/repo1/src/branch/master/README.md", postData)
+	resp = session.MakeRequest(t, req, http.StatusFound)
+	location := resp.HeaderMap.Get("Location")
+	assert.Equal(t, "/user2/repo1/src/branch/main/README.md", location)
+
+	// check db
+	repo1 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	assert.Equal(t, "main", repo1.DefaultBranch)
+}
diff --git a/models/branches.go b/models/branches.go
index 8eaa4b6fd7..3c62c7a87b 100644
--- a/models/branches.go
+++ b/models/branches.go
@@ -53,6 +53,7 @@ type ProtectedBranch struct {
 func init() {
 	db.RegisterModel(new(ProtectedBranch))
 	db.RegisterModel(new(DeletedBranch))
+	db.RegisterModel(new(RenamedBranch))
 }
 
 // IsProtected returns if the branch is protected
@@ -588,3 +589,83 @@ func RemoveOldDeletedBranches(ctx context.Context, olderThan time.Duration) {
 		log.Error("DeletedBranchesCleanup: %v", err)
 	}
 }
+
+// RenamedBranch provide renamed branch log
+// will check it when a branch can't be found
+type RenamedBranch struct {
+	ID          int64 `xorm:"pk autoincr"`
+	RepoID      int64 `xorm:"INDEX NOT NULL"`
+	From        string
+	To          string
+	CreatedUnix timeutil.TimeStamp `xorm:"created"`
+}
+
+// FindRenamedBranch check if a branch was renamed
+func FindRenamedBranch(repoID int64, from string) (branch *RenamedBranch, exist bool, err error) {
+	branch = &RenamedBranch{
+		RepoID: repoID,
+		From:   from,
+	}
+	exist, err = db.GetEngine(db.DefaultContext).Get(branch)
+
+	return
+}
+
+// RenameBranch rename a branch
+func (repo *Repository) RenameBranch(from, to string, gitAction func(isDefault bool) error) (err error) {
+	sess := db.NewSession(db.DefaultContext)
+	defer sess.Close()
+	if err := sess.Begin(); err != nil {
+		return err
+	}
+
+	// 1. update default branch if needed
+	isDefault := repo.DefaultBranch == from
+	if isDefault {
+		repo.DefaultBranch = to
+		_, err = sess.ID(repo.ID).Cols("default_branch").Update(repo)
+		if err != nil {
+			return err
+		}
+	}
+
+	// 2. Update protected branch if needed
+	protectedBranch, err := getProtectedBranchBy(sess, repo.ID, from)
+	if err != nil {
+		return err
+	}
+
+	if protectedBranch != nil {
+		protectedBranch.BranchName = to
+		_, err = sess.ID(protectedBranch.ID).Cols("branch_name").Update(protectedBranch)
+		if err != nil {
+			return err
+		}
+	}
+
+	// 3. Update all not merged pull request base branch name
+	_, err = sess.Table(new(PullRequest)).Where("base_repo_id=? AND base_branch=? AND has_merged=?",
+		repo.ID, from, false).
+		Update(map[string]interface{}{"base_branch": to})
+	if err != nil {
+		return err
+	}
+
+	// 4. do git action
+	if err = gitAction(isDefault); err != nil {
+		return err
+	}
+
+	// 5. insert renamed branch record
+	renamedBranch := &RenamedBranch{
+		RepoID: repo.ID,
+		From:   from,
+		To:     to,
+	}
+	_, err = sess.Insert(renamedBranch)
+	if err != nil {
+		return err
+	}
+
+	return sess.Commit()
+}
diff --git a/models/branches_test.go b/models/branches_test.go
index 02a9e81a7e..f1dcfecfa8 100644
--- a/models/branches_test.go
+++ b/models/branches_test.go
@@ -79,3 +79,52 @@ func getDeletedBranch(t *testing.T, branch *DeletedBranch) *DeletedBranch {
 
 	return deletedBranch
 }
+
+func TestFindRenamedBranch(t *testing.T) {
+	assert.NoError(t, db.PrepareTestDatabase())
+	branch, exist, err := FindRenamedBranch(1, "dev")
+	assert.NoError(t, err)
+	assert.Equal(t, true, exist)
+	assert.Equal(t, "master", branch.To)
+
+	_, exist, err = FindRenamedBranch(1, "unknow")
+	assert.NoError(t, err)
+	assert.Equal(t, false, exist)
+}
+
+func TestRenameBranch(t *testing.T) {
+	assert.NoError(t, db.PrepareTestDatabase())
+	repo1 := db.AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
+	_isDefault := false
+
+	err := UpdateProtectBranch(repo1, &ProtectedBranch{
+		RepoID:     repo1.ID,
+		BranchName: "master",
+	}, WhitelistOptions{})
+	assert.NoError(t, err)
+
+	assert.NoError(t, repo1.RenameBranch("master", "main", func(isDefault bool) error {
+		_isDefault = isDefault
+		return nil
+	}))
+
+	assert.Equal(t, true, _isDefault)
+	repo1 = db.AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
+	assert.Equal(t, "main", repo1.DefaultBranch)
+
+	pull := db.AssertExistsAndLoadBean(t, &PullRequest{ID: 1}).(*PullRequest) // merged
+	assert.Equal(t, "master", pull.BaseBranch)
+
+	pull = db.AssertExistsAndLoadBean(t, &PullRequest{ID: 2}).(*PullRequest) // open
+	assert.Equal(t, "main", pull.BaseBranch)
+
+	renamedBranch := db.AssertExistsAndLoadBean(t, &RenamedBranch{ID: 2}).(*RenamedBranch)
+	assert.Equal(t, "master", renamedBranch.From)
+	assert.Equal(t, "main", renamedBranch.To)
+	assert.Equal(t, int64(1), renamedBranch.RepoID)
+
+	db.AssertExistsAndLoadBean(t, &ProtectedBranch{
+		RepoID:     repo1.ID,
+		BranchName: "main",
+	})
+}
diff --git a/models/fixtures/renamed_branch.yml b/models/fixtures/renamed_branch.yml
new file mode 100644
index 0000000000..efa5130a2b
--- /dev/null
+++ b/models/fixtures/renamed_branch.yml
@@ -0,0 +1,5 @@
+-
+  id: 1
+  repo_id: 1
+  from: dev
+  to: master
diff --git a/models/migrations/migrations.go b/models/migrations/migrations.go
index 33b094e48c..6f6296dabf 100644
--- a/models/migrations/migrations.go
+++ b/models/migrations/migrations.go
@@ -346,6 +346,8 @@ var migrations = []Migration{
 	NewMigration("Add table commit_status_index", addTableCommitStatusIndex),
 	// v196 -> v197
 	NewMigration("Add Color to ProjectBoard table", addColorColToProjectBoard),
+	// v197 -> v198
+	NewMigration("Add renamed_branch table", addRenamedBranchTable),
 }
 
 // GetCurrentDBVersion returns the current db version
diff --git a/models/migrations/v197.go b/models/migrations/v197.go
new file mode 100644
index 0000000000..3517896a23
--- /dev/null
+++ b/models/migrations/v197.go
@@ -0,0 +1,20 @@
+// Copyright 2021 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 migrations
+
+import (
+	"xorm.io/xorm"
+)
+
+func addRenamedBranchTable(x *xorm.Engine) error {
+	type RenamedBranch struct {
+		ID          int64 `xorm:"pk autoincr"`
+		RepoID      int64 `xorm:"INDEX NOT NULL"`
+		From        string
+		To          string
+		CreatedUnix int64 `xorm:"created"`
+	}
+	return x.Sync2(new(RenamedBranch))
+}
diff --git a/modules/context/repo.go b/modules/context/repo.go
index eceefd9e59..8972cd28bc 100644
--- a/modules/context/repo.go
+++ b/modules/context/repo.go
@@ -705,7 +705,28 @@ func getRefName(ctx *Context, pathType RepoRefType) string {
 		ctx.Repo.TreePath = path
 		return ctx.Repo.Repository.DefaultBranch
 	case RepoRefBranch:
-		return getRefNameFromPath(ctx, path, ctx.Repo.GitRepo.IsBranchExist)
+		ref := getRefNameFromPath(ctx, path, ctx.Repo.GitRepo.IsBranchExist)
+		if len(ref) == 0 {
+			// maybe it's a renamed branch
+			return getRefNameFromPath(ctx, path, func(s string) bool {
+				b, exist, err := models.FindRenamedBranch(ctx.Repo.Repository.ID, s)
+				if err != nil {
+					log.Error("FindRenamedBranch", err)
+					return false
+				}
+
+				if !exist {
+					return false
+				}
+
+				ctx.Data["IsRenamedBranch"] = true
+				ctx.Data["RenamedBranchName"] = b.To
+
+				return true
+			})
+		}
+
+		return ref
 	case RepoRefTag:
 		return getRefNameFromPath(ctx, path, ctx.Repo.GitRepo.IsTagExist)
 	case RepoRefCommit:
@@ -784,6 +805,15 @@ func RepoRefByType(refType RepoRefType, ignoreNotExistErr ...bool) func(*Context
 		} else {
 			refName = getRefName(ctx, refType)
 			ctx.Repo.BranchName = refName
+			isRenamedBranch, has := ctx.Data["IsRenamedBranch"].(bool)
+			if isRenamedBranch && has {
+				renamedBranchName := ctx.Data["RenamedBranchName"].(string)
+				ctx.Flash.Info(ctx.Tr("repo.branch.renamed", refName, renamedBranchName))
+				link := strings.Replace(ctx.Req.RequestURI, refName, renamedBranchName, 1)
+				ctx.Redirect(link)
+				return
+			}
+
 			if refType.RefTypeIncludesBranches() && ctx.Repo.GitRepo.IsBranchExist(refName) {
 				ctx.Repo.IsViewBranch = true
 
diff --git a/modules/git/repo_branch.go b/modules/git/repo_branch.go
index 7c30b1fb20..96f692826e 100644
--- a/modules/git/repo_branch.go
+++ b/modules/git/repo_branch.go
@@ -164,3 +164,9 @@ func (repo *Repository) RemoveRemote(name string) error {
 func (branch *Branch) GetCommit() (*Commit, error) {
 	return branch.gitRepo.GetBranchCommit(branch.Name)
 }
+
+// RenameBranch rename a branch
+func (repo *Repository) RenameBranch(from, to string) error {
+	_, err := NewCommand("branch", "-m", from, to).RunInDir(repo.Path)
+	return err
+}
diff --git a/options/locale/locale_en-US.ini b/options/locale/locale_en-US.ini
index bc03f86619..d5af933f40 100644
--- a/options/locale/locale_en-US.ini
+++ b/options/locale/locale_en-US.ini
@@ -1985,6 +1985,12 @@ settings.lfs_pointers.inRepo=In Repo
 settings.lfs_pointers.exists=Exists in store
 settings.lfs_pointers.accessible=Accessible to User
 settings.lfs_pointers.associateAccessible=Associate accessible %d OIDs
+settings.rename_branch_failed_exist=Cannot rename branch because target branch %s exists.
+settings.rename_branch_failed_not_exist=Cannot rename branch %s because it does not exist.
+settings.rename_branch_success =Branch %s was successfully renamed to %s.
+settings.rename_branch_from=old branch name
+settings.rename_branch_to=new branch name
+settings.rename_branch=Rename branch
 
 diff.browse_source = Browse Source
 diff.parent = parent
@@ -2106,6 +2112,7 @@ branch.create_new_branch = Create branch from branch:
 branch.confirm_create_branch = Create branch
 branch.new_branch = Create new branch
 branch.new_branch_from = Create new branch from '%s'
+branch.renamed = Branch %s was renamed to %s.
 
 tag.create_tag = Create tag <strong>%s</strong>
 tag.create_success = Tag '%s' has been created.
diff --git a/routers/web/repo/setting_protected_branch.go b/routers/web/repo/setting_protected_branch.go
index c48ab9471a..876ff9ba46 100644
--- a/routers/web/repo/setting_protected_branch.go
+++ b/routers/web/repo/setting_protected_branch.go
@@ -19,6 +19,7 @@ import (
 	"code.gitea.io/gitea/modules/web"
 	"code.gitea.io/gitea/services/forms"
 	pull_service "code.gitea.io/gitea/services/pull"
+	"code.gitea.io/gitea/services/repository"
 )
 
 // ProtectedBranch render the page to protect the repository
@@ -285,3 +286,40 @@ func SettingsProtectedBranchPost(ctx *context.Context) {
 		ctx.Redirect(fmt.Sprintf("%s/settings/branches", ctx.Repo.RepoLink))
 	}
 }
+
+// RenameBranchPost responses for rename a branch
+func RenameBranchPost(ctx *context.Context) {
+	form := web.GetForm(ctx).(*forms.RenameBranchForm)
+
+	if !ctx.Repo.CanCreateBranch() {
+		ctx.NotFound("RenameBranch", nil)
+		return
+	}
+
+	if ctx.HasError() {
+		ctx.Flash.Error(ctx.GetErrMsg())
+		ctx.Redirect(fmt.Sprintf("%s/settings/branches", ctx.Repo.RepoLink))
+		return
+	}
+
+	msg, err := repository.RenameBranch(ctx.Repo.Repository, ctx.User, ctx.Repo.GitRepo, form.From, form.To)
+	if err != nil {
+		ctx.ServerError("RenameBranch", err)
+		return
+	}
+
+	if msg == "target_exist" {
+		ctx.Flash.Error(ctx.Tr("repo.settings.rename_branch_failed_exist", form.To))
+		ctx.Redirect(fmt.Sprintf("%s/settings/branches", ctx.Repo.RepoLink))
+		return
+	}
+
+	if msg == "from_not_exist" {
+		ctx.Flash.Error(ctx.Tr("repo.settings.rename_branch_failed_not_exist", form.From))
+		ctx.Redirect(fmt.Sprintf("%s/settings/branches", ctx.Repo.RepoLink))
+		return
+	}
+
+	ctx.Flash.Success(ctx.Tr("repo.settings.rename_branch_success", form.From, form.To))
+	ctx.Redirect(fmt.Sprintf("%s/settings/branches", ctx.Repo.RepoLink))
+}
diff --git a/routers/web/web.go b/routers/web/web.go
index 01d90d206f..b4103ccad3 100644
--- a/routers/web/web.go
+++ b/routers/web/web.go
@@ -612,6 +612,7 @@ func RegisterRoutes(m *web.Route) {
 				m.Combo("/*").Get(repo.SettingsProtectedBranch).
 					Post(bindIgnErr(forms.ProtectBranchForm{}), context.RepoMustNotBeArchived(), repo.SettingsProtectedBranchPost)
 			}, repo.MustBeNotEmpty)
+			m.Post("/rename_branch", bindIgnErr(forms.RenameBranchForm{}), context.RepoMustNotBeArchived(), repo.RenameBranchPost)
 
 			m.Group("/tags", func() {
 				m.Get("", repo.Tags)
diff --git a/services/forms/repo_branch_form.go b/services/forms/repo_branch_form.go
index 88a069b831..f9262aaede 100644
--- a/services/forms/repo_branch_form.go
+++ b/services/forms/repo_branch_form.go
@@ -24,3 +24,15 @@ func (f *NewBranchForm) Validate(req *http.Request, errs binding.Errors) binding
 	ctx := context.GetContext(req)
 	return middleware.Validate(errs, ctx.Data, f, ctx.Locale)
 }
+
+// RenameBranchForm form for rename a branch
+type RenameBranchForm struct {
+	From string `binding:"Required;MaxSize(100);GitRefName"`
+	To   string `binding:"Required;MaxSize(100);GitRefName"`
+}
+
+// Validate validates the fields
+func (f *RenameBranchForm) Validate(req *http.Request, errs binding.Errors) binding.Errors {
+	ctx := context.GetContext(req)
+	return middleware.Validate(errs, ctx.Data, f, ctx.Locale)
+}
diff --git a/services/repository/branch.go b/services/repository/branch.go
index 28d24f121d..5e246cbec6 100644
--- a/services/repository/branch.go
+++ b/services/repository/branch.go
@@ -10,10 +10,49 @@ import (
 	"code.gitea.io/gitea/models"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/notification"
 	repo_module "code.gitea.io/gitea/modules/repository"
 	pull_service "code.gitea.io/gitea/services/pull"
 )
 
+// RenameBranch rename a branch
+func RenameBranch(repo *models.Repository, doer *models.User, gitRepo *git.Repository, from, to string) (string, error) {
+	if from == to {
+		return "target_exist", nil
+	}
+
+	if gitRepo.IsBranchExist(to) {
+		return "target_exist", nil
+	}
+
+	if !gitRepo.IsBranchExist(from) {
+		return "from_not_exist", nil
+	}
+
+	if err := repo.RenameBranch(from, to, func(isDefault bool) error {
+		err2 := gitRepo.RenameBranch(from, to)
+		if err2 != nil {
+			return err2
+		}
+
+		if isDefault {
+			err2 = gitRepo.SetDefaultBranch(to)
+			if err2 != nil {
+				return err2
+			}
+		}
+
+		return nil
+	}); err != nil {
+		return "", err
+	}
+
+	notification.NotifyDeleteRef(doer, repo, "branch", "refs/heads/"+from)
+	notification.NotifyCreateRef(doer, repo, "branch", "refs/heads/"+to)
+
+	return "", nil
+}
+
 // enmuerates all branch related errors
 var (
 	ErrBranchIsDefault   = errors.New("branch is default")
diff --git a/templates/repo/settings/branches.tmpl b/templates/repo/settings/branches.tmpl
index ccf6abbb81..89d7c6db77 100644
--- a/templates/repo/settings/branches.tmpl
+++ b/templates/repo/settings/branches.tmpl
@@ -77,6 +77,28 @@
 					</div>
 				</div>
 			</div>
+
+			{{if $.Repository.CanCreateBranch}}
+				<h4 class="ui top attached header">
+					{{.i18n.Tr "repo.settings.rename_branch"}}
+				</h4>
+				<div class="ui attached segment">
+					<form class="ui form" action="{{$.Repository.Link}}/settings/rename_branch" method="post">
+						{{.CsrfTokenHtml}}
+						<div class="required field">
+							<label for="from">{{.i18n.Tr "repo.settings.rename_branch_from"}}</label>
+							<input id="from" name="from" required>
+						</div>
+						<div class="required field {{if .Err_BranchName}}error{{end}}">
+							<label for="to">{{.i18n.Tr "repo.settings.rename_branch_to"}}</label>
+							<input id="to" name="to" required>
+						</div>
+						<div class="field">
+							<button class="ui green button">{{$.i18n.Tr "repo.settings.update_settings"}}</button>
+						</div>
+					</form>
+				</div>
+			{{end}}
 		{{end}}
 	</div>
 </div>