Allow configuring default PR base branch (fixes #36412) (#36425)

This adds a per-repository default PR base branch and wires it through PR entry points. It updates compare links and recently pushed branch prompts to respect the configured base branch, and prevents auto-merge cleanup from deleting the configured base branch on same-repo PRs. ## Behavior changes - New PR compare links on repo home/issue list and branch list honor the configured default PR base branch. - The "recently pushed new branches" prompt now compares against the configured base branch. - Auto-merge branch cleanup skips deleting the configured base branch (same-repo PRs only). --------- Signed-off-by: Louis <116039387+tototomate123@users.noreply.github.com> Co-authored-by: wxiaoguang <wxiaoguang@gmail.com> Co-authored-by: silverwind <me@silverwind.io>
2026-02-07 14:25:11 +01:00 · 2026-02-07 02:34:29 +01:00 · 2026-02-07 02:34:29 +01:00 · e2104a1dd5
commit e2104a1dd5
parent 0dacd956fb
25 changed files with 213 additions and 99 deletions
--- a/models/git/branch.go
+++ b/models/git/branch.go
@ -490,12 +490,25 @@ func FindRecentlyPushedNewBranches(ctx context.Context, doer *user_model.User, o
 		opts.CommitAfterUnix = time.Now().Add(-time.Hour * 2).Unix()
 	}

-	baseBranch, err := GetBranch(ctx, opts.BaseRepo.ID, opts.BaseRepo.DefaultBranch)
+	var ignoredCommitIDs []string
+	baseDefaultBranch, err := GetBranch(ctx, opts.BaseRepo.ID, opts.BaseRepo.DefaultBranch)
 	if err != nil {
-		return nil, err
+		log.Warn("GetBranch:DefaultBranch: %v", err)
+	} else {
+		ignoredCommitIDs = append(ignoredCommitIDs, baseDefaultBranch.CommitID)
 	}

-	// find all related branches, these branches may already created PRs, we will check later
+	baseDefaultTargetBranchName := opts.BaseRepo.MustGetUnit(ctx, unit.TypePullRequests).PullRequestsConfig().DefaultTargetBranch
+	if baseDefaultTargetBranchName != "" && baseDefaultTargetBranchName != opts.BaseRepo.DefaultBranch {
+		baseDefaultTargetBranch, err := GetBranch(ctx, opts.BaseRepo.ID, baseDefaultTargetBranchName)
+		if err != nil {
+			log.Warn("GetBranch:DefaultTargetBranch: %v", err)
+		} else {
+			ignoredCommitIDs = append(ignoredCommitIDs, baseDefaultTargetBranch.CommitID)
+		}
+	}
+
+	// find all related branches, these branches may already have PRs, we will check later
 	var branches []*Branch
 	if err := db.GetEngine(ctx).
 		Where(builder.And(
@ -506,7 +519,7 @@ func FindRecentlyPushedNewBranches(ctx context.Context, doer *user_model.User, o
 			builder.Gte{"commit_time": opts.CommitAfterUnix},
 			builder.In("repo_id", repoIDs),
 			// newly created branch have no changes, so skip them
-			builder.Neq{"commit_id": baseBranch.CommitID},
+			builder.NotIn("commit_id", ignoredCommitIDs),
 		)).
 		OrderBy(db.SearchOrderByRecentUpdated.String()).
 		Find(&branches); err != nil {
@ -514,10 +527,8 @@ func FindRecentlyPushedNewBranches(ctx context.Context, doer *user_model.User, o
 	}

 	newBranches := make([]*RecentlyPushedNewBranch, 0, len(branches))
-	if opts.MaxCount == 0 {
-		// by default we display 2 recently pushed new branch
-		opts.MaxCount = 2
-	}
+	opts.MaxCount = util.IfZero(opts.MaxCount, 2) // by default, we display 2 recently pushed new branch
+	baseTargetBranchName := opts.BaseRepo.GetPullRequestTargetBranch(ctx)
 	for _, branch := range branches {
 		// whether the branch is protected
 		protected, err := IsBranchProtected(ctx, branch.RepoID, branch.Name)
@ -555,7 +566,7 @@ func FindRecentlyPushedNewBranches(ctx context.Context, doer *user_model.User, o
 				BranchDisplayName: branchDisplayName,
 				BranchName:        branch.Name,
 				BranchLink:        fmt.Sprintf("%s/src/branch/%s", branch.Repo.Link(), util.PathEscapeSegments(branch.Name)),
-				BranchCompareURL:  branch.Repo.ComposeBranchCompareURL(opts.BaseRepo, branch.Name),
+				BranchCompareURL:  branch.Repo.ComposeBranchCompareURL(opts.BaseRepo, baseTargetBranchName, branch.Name),
 				CommitTime:        branch.CommitTime,
 			})
 		}
--- a/models/repo/pull_request_default.go
+++ b/models/repo/pull_request_default.go
@ -0,0 +1,16 @@
+// Copyright 2026 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package repo
+
+import (
+	"context"
+
+	"code.gitea.io/gitea/models/unit"
+	"code.gitea.io/gitea/modules/util"
+)
+
+func (repo *Repository) GetPullRequestTargetBranch(ctx context.Context) string {
+	unitPRConfig := repo.MustGetUnit(ctx, unit.TypePullRequests).PullRequestsConfig()
+	return util.IfZero(unitPRConfig.DefaultTargetBranch, repo.DefaultBranch)
+}
--- a/models/repo/pull_request_default_test.go
+++ b/models/repo/pull_request_default_test.go
@ -0,0 +1,32 @@
+// Copyright 2026 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package repo
+
+import (
+	"testing"
+
+	"code.gitea.io/gitea/models/unit"
+	"code.gitea.io/gitea/models/unittest"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestDefaultTargetBranchSelection(t *testing.T) {
+	assert.NoError(t, unittest.PrepareTestDatabase())
+
+	ctx := t.Context()
+	repo := unittest.AssertExistsAndLoadBean(t, &Repository{ID: 1})
+
+	assert.Equal(t, repo.DefaultBranch, repo.GetPullRequestTargetBranch(ctx))
+
+	repo.Units = nil
+	prUnit, err := repo.GetUnit(ctx, unit.TypePullRequests)
+	assert.NoError(t, err)
+	prConfig := prUnit.PullRequestsConfig()
+	prConfig.DefaultTargetBranch = "branch2"
+	prUnit.Config = prConfig
+	assert.NoError(t, UpdateRepoUnit(ctx, prUnit))
+	repo.Units = nil
+	assert.Equal(t, "branch2", repo.GetPullRequestTargetBranch(ctx))
+}
--- a/models/repo/repo.go
+++ b/models/repo/repo.go
@ -613,16 +613,13 @@ func (repo *Repository) ComposeCompareURL(oldCommitID, newCommitID string) strin
 	return fmt.Sprintf("%s/%s/compare/%s...%s", url.PathEscape(repo.OwnerName), url.PathEscape(repo.Name), util.PathEscapeSegments(oldCommitID), util.PathEscapeSegments(newCommitID))
 }

-func (repo *Repository) ComposeBranchCompareURL(baseRepo *Repository, branchName string) string {
-	if baseRepo == nil {
-		baseRepo = repo
-	}
+func (repo *Repository) ComposeBranchCompareURL(baseRepo *Repository, baseBranch, branchName string) string {
 	var cmpBranchEscaped string
 	if repo.ID != baseRepo.ID {
 		cmpBranchEscaped = fmt.Sprintf("%s/%s:", url.PathEscape(repo.OwnerName), url.PathEscape(repo.Name))
 	}
 	cmpBranchEscaped = fmt.Sprintf("%s%s", cmpBranchEscaped, util.PathEscapeSegments(branchName))
-	return fmt.Sprintf("%s/compare/%s...%s", baseRepo.Link(), util.PathEscapeSegments(baseRepo.DefaultBranch), cmpBranchEscaped)
+	return fmt.Sprintf("%s/compare/%s...%s", baseRepo.Link(), util.PathEscapeSegments(baseBranch), cmpBranchEscaped)
 }

 // IsOwnedBy returns true when user owns this repository
--- a/models/repo/repo_unit.go
+++ b/models/repo/repo_unit.go
@ -131,6 +131,7 @@ type PullRequestsConfig struct {
 	DefaultDeleteBranchAfterMerge bool
 	DefaultMergeStyle             MergeStyle
 	DefaultAllowMaintainerEdit    bool
+	DefaultTargetBranch           string
 }

 // FromDB fills up a PullRequestsConfig from serialized format.
--- a/modules/structs/repo.go
+++ b/modules/structs/repo.go
@ -58,26 +58,27 @@ type Repository struct {
 	Fork        bool   `json:"fork"`
 	Template    bool   `json:"template"`
 	// the original repository if this repository is a fork, otherwise null
-	Parent        *Repository `json:"parent,omitempty"`
-	Mirror        bool        `json:"mirror"`
-	Size          int         `json:"size"`
-	Language      string      `json:"language"`
-	LanguagesURL  string      `json:"languages_url"`
-	HTMLURL       string      `json:"html_url"`
-	URL           string      `json:"url"`
-	Link          string      `json:"link"`
-	SSHURL        string      `json:"ssh_url"`
-	CloneURL      string      `json:"clone_url"`
-	OriginalURL   string      `json:"original_url"`
-	Website       string      `json:"website"`
-	Stars         int         `json:"stars_count"`
-	Forks         int         `json:"forks_count"`
-	Watchers      int         `json:"watchers_count"`
-	OpenIssues    int         `json:"open_issues_count"`
-	OpenPulls     int         `json:"open_pr_counter"`
-	Releases      int         `json:"release_counter"`
-	DefaultBranch string      `json:"default_branch"`
-	Archived      bool        `json:"archived"`
+	Parent              *Repository `json:"parent,omitempty"`
+	Mirror              bool        `json:"mirror"`
+	Size                int         `json:"size"`
+	Language            string      `json:"language"`
+	LanguagesURL        string      `json:"languages_url"`
+	HTMLURL             string      `json:"html_url"`
+	URL                 string      `json:"url"`
+	Link                string      `json:"link"`
+	SSHURL              string      `json:"ssh_url"`
+	CloneURL            string      `json:"clone_url"`
+	OriginalURL         string      `json:"original_url"`
+	Website             string      `json:"website"`
+	Stars               int         `json:"stars_count"`
+	Forks               int         `json:"forks_count"`
+	Watchers            int         `json:"watchers_count"`
+	OpenIssues          int         `json:"open_issues_count"`
+	OpenPulls           int         `json:"open_pr_counter"`
+	Releases            int         `json:"release_counter"`
+	DefaultBranch       string      `json:"default_branch"`
+	DefaultTargetBranch string      `json:"default_target_branch,omitempty"`
+	Archived            bool        `json:"archived"`
 	// swagger:strfmt date-time
 	Created time.Time `json:"created_at"`
 	// swagger:strfmt date-time
--- a/options/locale/locale_en-US.json
+++ b/options/locale/locale_en-US.json
@ -2124,6 +2124,8 @@
  "repo.settings.pulls.ignore_whitespace": "Ignore Whitespace for Conflicts",
  "repo.settings.pulls.enable_autodetect_manual_merge": "Enable autodetect manual merge (Note: In some special cases, misjudgments can occur)",
  "repo.settings.pulls.allow_rebase_update": "Enable updating pull request branch by rebase",
+  "repo.settings.pulls.default_target_branch": "Default target branch for new pull requests",
+  "repo.settings.pulls.default_target_branch_default": "Default branch (%s)",
  "repo.settings.pulls.default_delete_branch_after_merge": "Delete pull request branch after merge by default",
  "repo.settings.pulls.default_allow_edits_from_maintainers": "Allow edits from maintainers by default",
  "repo.settings.releases_desc": "Enable Repository Releases",
@ -2436,9 +2438,10 @@
  "repo.settings.block_outdated_branch_desc": "Merging will not be possible when head branch is behind base branch.",
  "repo.settings.block_admin_merge_override": "Administrators must follow branch protection rules",
  "repo.settings.block_admin_merge_override_desc": "Administrators must follow branch protection rules and cannot circumvent it.",
-  "repo.settings.default_branch_desc": "Select a default repository branch for pull requests and code commits:",
+  "repo.settings.default_branch_desc": "Select a default branch for code commits.",
+  "repo.settings.default_target_branch_desc": "Pull requests can use different default target branch if it is set in the Pull Requests section of Repository Advance Settings.",
  "repo.settings.merge_style_desc": "Merge Styles",
-  "repo.settings.default_merge_style_desc": "Default Merge Style",
+  "repo.settings.default_merge_style_desc": "Default merge style",
  "repo.settings.choose_branch": "Choose a branch…",
  "repo.settings.no_protected_branch": "There are no protected branches.",
  "repo.settings.edit_protected_branch": "Edit",
@ -2650,7 +2653,7 @@
  "repo.branch.restore_success": "Branch \"%s\" has been restored.",
  "repo.branch.restore_failed": "Failed to restore branch \"%s\".",
  "repo.branch.protected_deletion_failed": "Branch \"%s\" is protected. It cannot be deleted.",
-  "repo.branch.default_deletion_failed": "Branch \"%s\" is the default branch. It cannot be deleted.",
+  "repo.branch.default_deletion_failed": "Branch \"%s\" is the default or pull request target branch. It cannot be deleted.",
  "repo.branch.default_branch_not_exist": "Default branch \"%s\" does not exist.",
  "repo.branch.restore": "Restore Branch \"%s\"",
  "repo.branch.download": "Download Branch \"%s\"",
--- a/routers/api/v1/repo/branch.go
+++ b/routers/api/v1/repo/branch.go
@ -155,7 +155,7 @@ func DeleteBranch(ctx *context.APIContext) {
 		case git.IsErrBranchNotExist(err):
 			ctx.APIErrorNotFound(err)
 		case errors.Is(err, repo_service.ErrBranchIsDefault):
-			ctx.APIError(http.StatusForbidden, errors.New("can not delete default branch"))
+			ctx.APIError(http.StatusForbidden, errors.New("can not delete default or pull request target branch"))
 		case errors.Is(err, git_model.ErrBranchIsProtected):
 			ctx.APIError(http.StatusForbidden, errors.New("branch protected"))
 		default:
--- a/routers/api/v1/repo/pull.go
+++ b/routers/api/v1/repo/pull.go
@ -1138,7 +1138,7 @@ func parseCompareInfo(ctx *context.APIContext, compareParam string) (result *git
 		return nil, nil
 	}

-	baseRef := ctx.Repo.GitRepo.UnstableGuessRefByShortName(util.IfZero(compareReq.BaseOriRef, baseRepo.DefaultBranch))
+	baseRef := ctx.Repo.GitRepo.UnstableGuessRefByShortName(util.IfZero(compareReq.BaseOriRef, baseRepo.GetPullRequestTargetBranch(ctx)))
 	headRef := headGitRepo.UnstableGuessRefByShortName(util.IfZero(compareReq.HeadOriRef, headRepo.DefaultBranch))

 	log.Trace("Repo path: %q, base ref: %q->%q, head ref: %q->%q", ctx.Repo.Repository.RelativePath(), compareReq.BaseOriRef, baseRef, compareReq.HeadOriRef, headRef)
--- a/routers/web/repo/branch.go
+++ b/routers/web/repo/branch.go
@ -41,6 +41,7 @@ func Branches(ctx *context.Context) {
 	ctx.Data["AllowsPulls"] = ctx.Repo.Repository.AllowsPulls(ctx)
 	ctx.Data["IsWriter"] = ctx.Repo.CanWrite(unit.TypeCode)
 	ctx.Data["IsMirror"] = ctx.Repo.Repository.IsMirror
+	// TODO: Can be replaced by ctx.Repo.PullRequestCtx.CanCreateNewPull()
 	ctx.Data["CanPull"] = ctx.Repo.CanWrite(unit.TypeCode) ||
 		(ctx.IsSigned && repo_model.HasForkedRepo(ctx, ctx.Doer.ID, ctx.Repo.Repository.ID))
 	ctx.Data["PageIsViewCode"] = true
--- a/routers/web/repo/compare.go
+++ b/routers/web/repo/compare.go
@ -247,7 +247,7 @@ func ParseCompareInfo(ctx *context.Context) *git_service.CompareInfo {
 	}

 	// 4 get base and head refs
-	baseRefName := util.IfZero(compareReq.BaseOriRef, baseRepo.DefaultBranch)
+	baseRefName := util.IfZero(compareReq.BaseOriRef, baseRepo.GetPullRequestTargetBranch(ctx))
 	headRefName := util.IfZero(compareReq.HeadOriRef, headRepo.DefaultBranch)

 	baseRef := ctx.Repo.GitRepo.UnstableGuessRefByShortName(baseRefName)
@ -276,10 +276,10 @@ func ParseCompareInfo(ctx *context.Context) *git_service.CompareInfo {
 	ctx.Data["BaseBranch"] = baseRef.ShortName() // for legacy templates
 	ctx.Data["HeadUser"] = headOwner
 	ctx.Data["HeadBranch"] = headRef.ShortName() // for legacy templates
-	ctx.Repo.PullRequest.SameRepo = isSameRepo
-
 	ctx.Data["IsPull"] = true

+	context.InitRepoPullRequestCtx(ctx, baseRepo, headRepo)
+
 	// The current base and head repositories and branches may not
 	// actually be the intended branches that the user wants to
 	// create a pull-request from - but also determining the head
--- a/routers/web/repo/issue.go
+++ b/routers/web/repo/issue.go
@ -109,11 +109,6 @@ func MustAllowPulls(ctx *context.Context) {
 		ctx.NotFound(nil)
 		return
 	}
-
-	// User can send pull request if owns a forked repository.
-	if ctx.IsSigned && repo_model.HasForkedRepo(ctx, ctx.Doer.ID, ctx.Repo.Repository.ID) {
-		ctx.Repo.PullRequest.Allowed = true
-	}
 }

 func retrieveProjectsInternal(ctx *context.Context, repo *repo_model.Repository) (open, closed []*project_model.Project) {
--- a/routers/web/repo/setting/setting.go
+++ b/routers/web/repo/setting/setting.go
@ -28,6 +28,7 @@ import (
 	"code.gitea.io/gitea/modules/util"
 	"code.gitea.io/gitea/modules/validation"
 	"code.gitea.io/gitea/modules/web"
+	repo_router "code.gitea.io/gitea/routers/web/repo"
 	actions_service "code.gitea.io/gitea/services/actions"
 	"code.gitea.io/gitea/services/context"
 	"code.gitea.io/gitea/services/forms"
@ -88,6 +89,11 @@ func SettingsCtxData(ctx *context.Context) {
 		return
 	}
 	ctx.Data["PushMirrors"] = pushMirrors
+
+	repo_router.PrepareBranchList(ctx)
+	if ctx.Written() {
+		return
+	}
 }

 // Settings show a repository's settings page
@ -622,6 +628,7 @@ func handleSettingsPostAdvanced(ctx *context.Context) {
 			DefaultDeleteBranchAfterMerge: form.DefaultDeleteBranchAfterMerge,
 			DefaultMergeStyle:             repo_model.MergeStyle(form.PullsDefaultMergeStyle),
 			DefaultAllowMaintainerEdit:    form.DefaultAllowMaintainerEdit,
+			DefaultTargetBranch:           strings.TrimSpace(form.DefaultTargetBranch),
 		}))
 	} else if !unit_model.TypePullRequests.UnitGlobalDisabled() {
 		deleteUnitTypes = append(deleteUnitTypes, unit_model.TypePullRequests)
--- a/services/context/api.go
+++ b/services/context/api.go
@ -221,7 +221,7 @@ func APIContexter() func(http.Handler) http.Handler {
 			ctx := &APIContext{
 				Base:  base,
 				Cache: cache.GetCache(),
-				Repo:  &Repository{PullRequest: &PullRequest{}},
+				Repo:  &Repository{},
 				Org:   &APIOrganization{},
 			}

--- a/services/context/context.go
+++ b/services/context/context.go
@ -129,7 +129,7 @@ func NewWebContext(base *Base, render Render, session session.Store) *Context {

 		Cache: cache.GetCache(),
 		Link:  setting.AppSubURL + strings.TrimSuffix(base.Req.URL.EscapedPath(), "/"),
-		Repo:  &Repository{PullRequest: &PullRequest{}},
+		Repo:  &Repository{},
 		Org:   &Organization{},
 	}
 	ctx.TemplateContext = NewTemplateContextForWeb(ctx)
--- a/services/context/repo.go
+++ b/services/context/repo.go
@ -37,11 +37,46 @@ import (
 	"github.com/editorconfig/editorconfig-core-go/v2"
 )

-// PullRequest contains information to make a pull request
-type PullRequest struct {
-	BaseRepo *repo_model.Repository
-	Allowed  bool // it only used by the web tmpl: "PullRequestCtx.Allowed"
-	SameRepo bool // it only used by the web tmpl: "PullRequestCtx.SameRepo"
+// PullRequestContext contains context information for making a new pull request
+type PullRequestContext struct {
+	ctx *Context
+
+	baseRepo, headRepo *repo_model.Repository
+
+	canCreateNewPull    *bool
+	defaultTargetBranch *string
+}
+
+func (prc *PullRequestContext) SameRepo() bool {
+	return prc.baseRepo != nil && prc.headRepo != nil && prc.baseRepo.ID == prc.headRepo.ID
+}
+
+func (prc *PullRequestContext) CanCreateNewPull() bool {
+	if prc.canCreateNewPull != nil {
+		return *prc.canCreateNewPull
+	}
+	ctx := prc.ctx
+	// People who have push access or have forked repository can propose a new pull request.
+	can := prc.baseRepo.CanContentChange() &&
+		(ctx.Repo.CanWrite(unit_model.TypeCode) || (ctx.IsSigned && repo_model.HasForkedRepo(ctx, ctx.Doer.ID, ctx.Repo.Repository.ID)))
+	prc.canCreateNewPull = &can
+	return can
+}
+
+func (prc *PullRequestContext) MakeDefaultCompareLink(headBranch string) string {
+	return prc.baseRepo.Link() + "/compare/" +
+		util.PathEscapeSegments(prc.DefaultTargetBranch()) + "..." +
+		util.Iif(prc.SameRepo(), "", util.PathEscapeSegments(prc.headRepo.OwnerName)+":") +
+		util.PathEscapeSegments(headBranch)
+}
+
+func (prc *PullRequestContext) DefaultTargetBranch() string {
+	if prc.defaultTargetBranch != nil {
+		return *prc.defaultTargetBranch
+	}
+	branchName := prc.baseRepo.GetPullRequestTargetBranch(prc.ctx)
+	prc.defaultTargetBranch = &branchName
+	return branchName
 }

 // Repository contains information to operate a repository
@ -64,7 +99,7 @@ type Repository struct {
 	CommitID     string
 	CommitsCount int64

-	PullRequest *PullRequest
+	PullRequestCtx *PullRequestContext
 }

 // CanWriteToBranch checks if the branch is writable by the user
@ -418,6 +453,12 @@ func repoAssignment(ctx *Context, repo *repo_model.Repository) {
 	ctx.Data["IsEmptyRepo"] = ctx.Repo.Repository.IsEmpty
 }

+func InitRepoPullRequestCtx(ctx *Context, base, head *repo_model.Repository) {
+	ctx.Repo.PullRequestCtx = &PullRequestContext{ctx: ctx}
+	ctx.Repo.PullRequestCtx.baseRepo, ctx.Repo.PullRequestCtx.headRepo = base, head
+	ctx.Data["PullRequestCtx"] = ctx.Repo.PullRequestCtx
+}
+
 // RepoAssignment returns a middleware to handle repository assignment
 func RepoAssignment(ctx *Context) {
 	if ctx.Data["Repository"] != nil {
@ -666,28 +707,16 @@ func RepoAssignment(ctx *Context) {

 	ctx.Data["BranchesCount"] = branchesTotal

-	// People who have push access or have forked repository can propose a new pull request.
-	canPush := ctx.Repo.CanWrite(unit_model.TypeCode) ||
-		(ctx.IsSigned && repo_model.HasForkedRepo(ctx, ctx.Doer.ID, ctx.Repo.Repository.ID))
-	canCompare := false
-
-	// Pull request is allowed if this is a fork repository
-	// and base repository accepts pull requests.
+	// Pull request is allowed if this is a fork repository, and base repository accepts pull requests.
 	if repo.BaseRepo != nil && repo.BaseRepo.AllowsPulls(ctx) {
-		canCompare = true
+		// TODO: this (and below) "BaseRepo" var is not clear and should be removed in the future
 		ctx.Data["BaseRepo"] = repo.BaseRepo
-		ctx.Repo.PullRequest.BaseRepo = repo.BaseRepo
-		ctx.Repo.PullRequest.Allowed = canPush
+		InitRepoPullRequestCtx(ctx, repo.BaseRepo, repo)
 	} else if repo.AllowsPulls(ctx) {
 		// Or, this is repository accepts pull requests between branches.
-		canCompare = true
 		ctx.Data["BaseRepo"] = repo
-		ctx.Repo.PullRequest.BaseRepo = repo
-		ctx.Repo.PullRequest.Allowed = canPush
-		ctx.Repo.PullRequest.SameRepo = true
+		InitRepoPullRequestCtx(ctx, repo, repo)
 	}
-	ctx.Data["CanCompareOrPull"] = canCompare
-	ctx.Data["PullRequestCtx"] = ctx.Repo.PullRequest

 	if ctx.Repo.Repository.Status == repo_model.RepositoryPendingTransfer {
 		repoTransfer, err := repo_model.GetPendingRepositoryTransfer(ctx, ctx.Repo.Repository)
--- a/services/convert/repository.go
+++ b/services/convert/repository.go
@ -103,6 +103,7 @@ func innerToRepo(ctx context.Context, repo *repo_model.Repository, permissionInR
 	defaultDeleteBranchAfterMerge := false
 	defaultMergeStyle := repo_model.MergeStyleMerge
 	defaultAllowMaintainerEdit := false
+	defaultTargetBranch := ""
 	if unit, err := repo.GetUnit(ctx, unit_model.TypePullRequests); err == nil {
 		config := unit.PullRequestsConfig()
 		hasPullRequests = true
@ -118,6 +119,7 @@ func innerToRepo(ctx context.Context, repo *repo_model.Repository, permissionInR
 		defaultDeleteBranchAfterMerge = config.DefaultDeleteBranchAfterMerge
 		defaultMergeStyle = config.GetDefaultMergeStyle()
 		defaultAllowMaintainerEdit = config.DefaultAllowMaintainerEdit
+		defaultTargetBranch = config.DefaultTargetBranch
 	}
 	hasProjects := false
 	projectsMode := repo_model.ProjectsModeAll
@ -235,6 +237,7 @@ func innerToRepo(ctx context.Context, repo *repo_model.Repository, permissionInR
 		DefaultDeleteBranchAfterMerge: defaultDeleteBranchAfterMerge,
 		DefaultMergeStyle:             string(defaultMergeStyle),
 		DefaultAllowMaintainerEdit:    defaultAllowMaintainerEdit,
+		DefaultTargetBranch:           defaultTargetBranch,
 		AvatarURL:                     repo.AvatarLink(ctx),
 		Internal:                      !repo.IsPrivate && repo.Owner.Visibility == api.VisibleTypePrivate,
 		MirrorInterval:                mirrorInterval,
--- a/services/forms/repo_form.go
+++ b/services/forms/repo_form.go
@ -143,6 +143,7 @@ type RepoSettingForm struct {
 	PullsAllowRebaseUpdate           bool
 	DefaultDeleteBranchAfterMerge    bool
 	DefaultAllowMaintainerEdit       bool
+	DefaultTargetBranch              string
 	EnableTimetracker                bool
 	AllowOnlyContributorsToTrackTime bool
 	EnableIssueDependencies          bool
--- a/services/repository/branch.go
+++ b/services/repository/branch.go
@ -547,10 +547,11 @@ func UpdateBranch(ctx context.Context, repo *repo_model.Repository, gitRepo *git
 	return gitrepo.Push(ctx, repo, repo, pushOpts)
 }

-var ErrBranchIsDefault = util.ErrorWrap(util.ErrPermissionDenied, "branch is default")
+var ErrBranchIsDefault = util.ErrorWrap(util.ErrPermissionDenied, "branch is default or pull request target")

 func CanDeleteBranch(ctx context.Context, repo *repo_model.Repository, branchName string, doer *user_model.User) error {
-	if branchName == repo.DefaultBranch {
+	unitPRConfig := repo.MustGetUnit(ctx, unit.TypePullRequests).PullRequestsConfig()
+	if branchName == repo.DefaultBranch || branchName == unitPRConfig.DefaultTargetBranch {
 		return ErrBranchIsDefault
 	}

--- a/templates/repo/branch/list.tmpl
+++ b/templates/repo/branch/list.tmpl
@ -133,14 +133,14 @@
 										<span class="ui orange large label" data-tooltip-content="{{ctx.Locale.Tr "repo.branch.included_desc"}}">
 											{{svg "octicon-git-pull-request"}} {{ctx.Locale.Tr "repo.branch.included"}}
 										</span>
-									{{else if and (not .DBBranch.IsDeleted) $.AllowsPulls (gt .CommitsAhead 0)}}
-									<a href="{{$.RepoLink}}/compare/{{PathEscapeSegments $.DefaultBranchBranch.DBBranch.Name}}...{{if ne $.Repository.Owner.Name $.Owner.Name}}{{PathEscape $.Owner.Name}}:{{end}}{{PathEscapeSegments .DBBranch.Name}}?expand=1">
+								{{else if and (not .DBBranch.IsDeleted) $.AllowsPulls (gt .CommitsAhead 0)}}
+									<a href="{{$.PullRequestCtx.MakeDefaultCompareLink .DBBranch.Name}}?expand=1">
 										<button id="new-pull-request" class="ui compact basic button tw-mr-0">{{if $.CanPull}}{{ctx.Locale.Tr "repo.pulls.compare_changes"}}{{else}}{{ctx.Locale.Tr "action.compare_branch"}}{{end}}</button>
 									</a>
 									{{end}}
 								{{else if and .LatestPullRequest.HasMerged .MergeMovedOn}}
 									{{if and (not .DBBranch.IsDeleted) $.AllowsPulls (gt .CommitsAhead 0)}}
-									<a href="{{$.RepoLink}}/compare/{{PathEscapeSegments $.DefaultBranchBranch.DBBranch.Name}}...{{if ne $.Repository.Owner.Name $.Owner.Name}}{{PathEscape $.Owner.Name}}:{{end}}{{PathEscapeSegments .DBBranch.Name}}?expand=1">
+									<a href="{{$.PullRequestCtx.MakeDefaultCompareLink .DBBranch.Name}}?expand=1">
 										<button id="new-pull-request" class="ui compact basic button tw-mr-0">{{if $.CanPull}}{{ctx.Locale.Tr "repo.pulls.compare_changes"}}{{else}}{{ctx.Locale.Tr "action.compare_branch"}}{{end}}</button>
 									</a>
 									{{end}}
--- a/templates/repo/issue/list.tmpl
+++ b/templates/repo/issue/list.tmpl
@ -24,11 +24,12 @@
 				{{if .PageIsIssueList}}
 					<a class="ui small primary button issue-list-new" href="{{.RepoLink}}/issues/new{{if .NewIssueChooseTemplate}}/choose{{end}}">{{ctx.Locale.Tr "repo.issues.new"}}</a>
 				{{else}}
-					<a class="ui small primary button new-pr-button issue-list-new{{if not .PullRequestCtx.Allowed}} disabled{{end}}" href="{{if .PullRequestCtx.Allowed}}{{.Repository.Link}}/compare/{{.Repository.DefaultBranch | PathEscapeSegments}}...{{if ne .Repository.Owner.Name .PullRequestCtx.BaseRepo.Owner.Name}}{{PathEscape .Repository.Owner.Name}}:{{end}}{{.Repository.DefaultBranch | PathEscapeSegments}}{{end}}">{{ctx.Locale.Tr "repo.pulls.new"}}</a>
+					<a class="ui small primary button new-pr-button issue-list-new {{if not .PullRequestCtx.CanCreateNewPull}}disabled{{end}}" href="{{.PullRequestCtx.MakeDefaultCompareLink .Repository.DefaultBranch}}">{{ctx.Locale.Tr "repo.pulls.new"}}</a>
 				{{end}}
 			{{else}}
+				{{/* archived, view compare page only */}}
 				{{if not .PageIsIssueList}}
-					<a class="ui small primary small button issue-list-new{{if not .PullRequestCtx.Allowed}} disabled{{end}}" href="{{if .PullRequestCtx.Allowed}}{{.PullRequestCtx.BaseRepo.Link}}/compare/{{.PullRequestCtx.BaseRepo.DefaultBranch | PathEscapeSegments}}...{{if ne .Repository.Owner.Name .PullRequestCtx.BaseRepo.Owner.Name}}{{PathEscape .Repository.Owner.Name}}:{{end}}{{.Repository.DefaultBranch | PathEscapeSegments}}{{end}}">{{ctx.Locale.Tr "action.compare_commits_general"}}</a>
+					<a class="ui small primary small button issue-list-new" href="{{.PullRequestCtx.MakeDefaultCompareLink .Repository.DefaultBranch}}">{{ctx.Locale.Tr "action.compare_commits_general"}}</a>
 				{{end}}
 			{{end}}
 		</div>
--- a/templates/repo/settings/branches.tmpl
+++ b/templates/repo/settings/branches.tmpl
@ -9,22 +9,23 @@
 				{{ctx.Locale.Tr "repo.default_branch"}}
 			</h4>
 			<div class="ui attached segment">
-				<p>
-					{{ctx.Locale.Tr "repo.settings.default_branch_desc"}}
-				</p>
-				<form class="tw-flex" action="{{.Link}}" method="post">
+				<p>{{ctx.Locale.Tr "repo.settings.default_branch_desc"}}</p>
+				<form class="ui form" action="{{.Link}}" method="post">
 					<input type="hidden" name="action" value="default_branch">
-					<div class="ui dropdown selection search tw-flex-1 tw-mr-2 tw-max-w-96">
-						{{svg "octicon-triangle-down" 14 "dropdown icon"}}
-						<input type="hidden" name="branch" value="{{.Repository.DefaultBranch}}">
-						<div class="default text">{{.Repository.DefaultBranch}}</div>
-						<div class="menu">
-							{{range .Branches}}
-								<div class="item" data-value="{{.}}">{{.}}</div>
-							{{end}}
+					<div class="flex-text-block">
+						<div class="ui dropdown selection search tw-flex-1 tw-mr-2 tw-max-w-96">
+							{{svg "octicon-triangle-down" 14 "dropdown icon"}}
+							<input type="hidden" name="branch" value="{{.Repository.DefaultBranch}}">
+							<div class="default text">{{.Repository.DefaultBranch}}</div>
+							<div class="menu">
+								{{range .Branches}}
+									<div class="item" data-value="{{.}}">{{.}}</div>
+								{{end}}
+							</div>
 						</div>
+						<button class="ui primary button"{{if .Repository.IsEmpty}} disabled{{end}}>{{ctx.Locale.Tr "repo.settings.branches.update_default_branch"}}</button>
 					</div>
-					<button class="ui primary button"{{if .Repository.IsEmpty}} disabled{{end}}>{{ctx.Locale.Tr "repo.settings.branches.update_default_branch"}}</button>
+					<div class="help tw-mt-4 tw-p-0">{{ctx.Locale.Tr "repo.settings.default_target_branch_desc"}}</div>
 				</form>
 			</div>

--- a/templates/repo/settings/options.tmpl
+++ b/templates/repo/settings/options.tmpl
@ -287,6 +287,7 @@
 			</div>
 		{{end}}

+		{{/* FIXME: need to split the "Advance Settings" by units, there are too many options here */}}
 		<h4 class="ui top attached header">
 			{{ctx.Locale.Tr "repo.settings.advanced_settings"}}
 		</h4>
@ -594,6 +595,20 @@
 								</div>
 							</div>
 						</div>
+						<div class="field">
+							<label>{{ctx.Locale.Tr "repo.settings.pulls.default_target_branch"}}</label>
+							<div class="ui search selection dropdown">
+								<input type="hidden" name="default_target_branch" value="{{$prUnit.PullRequestsConfig.DefaultTargetBranch}}">
+								<div class="default text"></div>
+								{{svg "octicon-triangle-down" 14 "dropdown icon"}}
+								<div class="menu">
+									<div class="item" data-value="">{{ctx.Locale.Tr "repo.settings.pulls.default_target_branch_default" $.Repository.DefaultBranch}}</div>
+									{{range $branchName := $.Branches}}
+										<div class="item" data-value="{{$branchName}}">{{$branchName}}</div>
+									{{end}}
+								</div>
+							</div>
+						</div>
 						<div class="field">
 							<div class="ui checkbox">
 								<input name="default_allow_maintainer_edit" type="checkbox" {{if or (not $pullRequestEnabled) ($prUnit.PullRequestsConfig.DefaultAllowMaintainerEdit)}}checked{{end}}>
--- a/templates/repo/view_content.tmpl
+++ b/templates/repo/view_content.tmpl
@ -20,15 +20,10 @@
 		"ShowViewAllRefsEntry" true
 	}}

-	{{if and .CanCompareOrPull .RefFullName.IsBranch (not .Repository.IsArchived)}}
-		{{$cmpBranch := ""}}
-		{{if ne .Repository.ID .BaseRepo.ID}}
-			{{$cmpBranch = printf "%s/%s:" (.Repository.OwnerName|PathEscape) (.Repository.Name|PathEscape)}}
-		{{end}}
-		{{$cmpBranch = print $cmpBranch (.BranchName|PathEscapeSegments)}}
-		{{$compareLink := printf "%s/compare/%s...%s" .BaseRepo.Link (.BaseRepo.DefaultBranch|PathEscapeSegments) $cmpBranch}}
+	{{if and .PullRequestCtx.CanCreateNewPull .RefFullName.IsBranch}}
+		{{$compareLink := .PullRequestCtx.MakeDefaultCompareLink .BranchName}}
 		<a id="new-pull-request" role="button" class="ui compact basic button" href="{{QueryBuild $compareLink "expand" 1}}"
-			data-tooltip-content="{{if .PullRequestCtx.Allowed}}{{ctx.Locale.Tr "repo.pulls.compare_changes"}}{{else}}{{ctx.Locale.Tr "action.compare_branch"}}{{end}}">
+			data-tooltip-content="{{ctx.Locale.Tr "repo.pulls.compare_changes"}}">
 			{{svg "octicon-git-pull-request"}}
 		</a>
 	{{end}}
--- a/templates/swagger/v1_json.tmpl
+++ b/templates/swagger/v1_json.tmpl
@ -28147,6 +28147,10 @@
          "type": "string",
          "x-go-name": "DefaultMergeStyle"
        },
+        "default_target_branch": {
+          "type": "string",
+          "x-go-name": "DefaultTargetBranch"
+        },
        "description": {
          "type": "string",
          "x-go-name": "Description"