Show branches and tags that contain a commit (#25180)

Now, you can see for a commit which existing branches and tags contain it.
You first have to click on the `load branches and tags` button, they are not preloaded by default.
All branches and tags are ordered descending by creation date.
You can even see without much hassle if the given commit is already part of the default branch.

Closes #25152 

## Screenshots

### Initial

![image](https://github.com/go-gitea/gitea/assets/51889757/84db2c0b-aaef-4f69-ab92-0b812793d2ad)

### Loaded

![image](https://github.com/go-gitea/gitea/assets/51889757/a9b84e66-8e44-4c55-b017-c37f4a45f41b)

---------

Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

16 files changed, 202 insertions, 42 deletions

diff --git a/modules/context/context_response.go b/modules/context/context_response.go
index bb3ccf69ce..9dc6d1fc0e 100644
--- a/modules/context/context_response.go
+++ b/modules/context/context_response.go
@@ -166,6 +166,7 @@ func (ctx *Context) serverErrorInternal(logMsg string, logErr error) {
 // NotFoundOrServerError use error check function to determine if the error
 // is about not found. It responds with 404 status code for not found error,
 // or error context description for logging purpose of 500 server error.
+// TODO: remove the "errCheck" and use util.ErrNotFound to check
 func (ctx *Context) NotFoundOrServerError(logMsg string, errCheck func(error) bool, logErr error) {
 	if errCheck(logErr) {
 		ctx.notFoundInternal(logMsg, logErr)
diff --git a/modules/git/commit.go b/modules/git/commit.go
index 729e3b4672..c44882d886 100644
--- a/modules/git/commit.go
+++ b/modules/git/commit.go
@@ -20,7 +20,6 @@ import (
 
 // Commit represents a git commit.
 type Commit struct {
-	Branch string // Branch this commit belongs to
 	Tree
 	ID            SHA1 // The ID of this commit object
 	Author        *Signature
@@ -432,31 +431,6 @@ func (c *Commit) GetBranchName() (string, error) {
 	return strings.SplitN(strings.TrimSpace(data), "~", 2)[0], nil
 }
 
-// LoadBranchName load branch name for commit
-func (c *Commit) LoadBranchName() (err error) {
-	if len(c.Branch) != 0 {
-		return nil
-	}
-
-	c.Branch, err = c.GetBranchName()
-	return err
-}
-
-// GetTagName gets the current tag name for given commit
-func (c *Commit) GetTagName() (string, error) {
-	data, _, err := NewCommand(c.repo.Ctx, "describe", "--exact-match", "--tags", "--always").AddDynamicArguments(c.ID.String()).RunStdString(&RunOpts{Dir: c.repo.Path})
-	if err != nil {
-		// handle special case where there is no tag for this commit
-		if strings.Contains(err.Error(), "no tag exactly matches") {
-			return "", nil
-		}
-
-		return "", err
-	}
-
-	return strings.TrimSpace(data), nil
-}
-
 // CommitFileStatus represents status of files in a commit.
 type CommitFileStatus struct {
 	Added    []string
diff --git a/modules/git/repo_ref.go b/modules/git/repo_ref.go
index 54e424bb83..8eaa17cb04 100644
--- a/modules/git/repo_ref.go
+++ b/modules/git/repo_ref.go
@@ -3,7 +3,61 @@
 
 package git
 
+import (
+	"context"
+	"strings"
+
+	"code.gitea.io/gitea/modules/util"
+)
+
 // GetRefs returns all references of the repository.
 func (repo *Repository) GetRefs() ([]*Reference, error) {
 	return repo.GetRefsFiltered("")
 }
+
+// ListOccurrences lists all refs of the given refType the given commit appears in sorted by creation date DESC
+// refType should only be a literal "branch" or "tag" and nothing else
+func (repo *Repository) ListOccurrences(ctx context.Context, refType, commitSHA string) ([]string, error) {
+	cmd := NewCommand(ctx)
+	if refType == "branch" {
+		cmd.AddArguments("branch")
+	} else if refType == "tag" {
+		cmd.AddArguments("tag")
+	} else {
+		return nil, util.NewInvalidArgumentErrorf(`can only use "branch" or "tag" for refType, but got %q`, refType)
+	}
+	stdout, _, err := cmd.AddArguments("--no-color", "--sort=-creatordate", "--contains").AddDynamicArguments(commitSHA).RunStdString(&RunOpts{Dir: repo.Path})
+	if err != nil {
+		return nil, err
+	}
+
+	refs := strings.Split(strings.TrimSpace(stdout), "\n")
+	if refType == "branch" {
+		return parseBranches(refs), nil
+	}
+	return parseTags(refs), nil
+}
+
+func parseBranches(refs []string) []string {
+	results := make([]string, 0, len(refs))
+	for _, ref := range refs {
+		if strings.HasPrefix(ref, "* ") { // current branch (main branch)
+			results = append(results, ref[len("* "):])
+		} else if strings.HasPrefix(ref, "  ") { // all other branches
+			results = append(results, ref[len("  "):])
+		} else if ref != "" {
+			results = append(results, ref)
+		}
+	}
+	return results
+}
+
+func parseTags(refs []string) []string {
+	results := make([]string, 0, len(refs))
+	for _, ref := range refs {
+		if ref != "" {
+			results = append(results, ref)
+		}
+	}
+	return results
+}
diff --git a/options/locale/locale_en-US.ini b/options/locale/locale_en-US.ini
index 25fb155435..dc88c422b5 100644
--- a/options/locale/locale_en-US.ini
+++ b/options/locale/locale_en-US.ini
@@ -1170,6 +1170,9 @@ commit_graph.select = Select branches
 commit_graph.hide_pr_refs = Hide Pull Requests
 commit_graph.monochrome = Mono
 commit_graph.color = Color
+commit.contained_in = This commit is contained in:
+commit.contained_in_default_branch = This commit is part of the default branch
+commit.load_referencing_branches_and_tags = Load branches and tags referencing this commit
 blame = Blame
 download_file = Download file
 normal_view = Normal View
diff --git a/routers/web/repo/commit.go b/routers/web/repo/commit.go
index e88f1139f8..5b32591b89 100644
--- a/routers/web/repo/commit.go
+++ b/routers/web/repo/commit.go
@@ -23,6 +23,7 @@ import (
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/services/gitdiff"
+	git_service "code.gitea.io/gitea/services/repository"
 )
 
 const (
@@ -255,6 +256,15 @@ func FileHistory(ctx *context.Context) {
 	ctx.HTML(http.StatusOK, tplCommits)
 }
 
+func LoadBranchesAndTags(ctx *context.Context) {
+	response, err := git_service.LoadBranchesAndTags(ctx, ctx.Repo, ctx.Params("sha"))
+	if err == nil {
+		ctx.JSON(http.StatusOK, response)
+		return
+	}
+	ctx.NotFoundOrServerError(fmt.Sprintf("could not load branches and tags the commit %s belongs to", ctx.Params("sha")), git.IsErrNotExist, err)
+}
+
 // Diff show different from current commit to previous commit
 func Diff(ctx *context.Context) {
 	ctx.Data["PageIsDiff"] = true
@@ -374,11 +384,6 @@ func Diff(ctx *context.Context) {
 		return
 	}
 
-	ctx.Data["TagName"], err = commit.GetTagName()
-	if err != nil {
-		ctx.ServerError("commit.GetTagName", err)
-		return
-	}
 	ctx.HTML(http.StatusOK, tplCommitPage)
 }
 
diff --git a/routers/web/web.go b/routers/web/web.go
index d7ef2fb82f..0b51961445 100644
--- a/routers/web/web.go
+++ b/routers/web/web.go
@@ -1337,6 +1337,7 @@ func registerRoutes(m *web.Route) {
 		m.Group("", func() {
 			m.Get("/graph", repo.Graph)
 			m.Get("/commit/{sha:([a-f0-9]{7,40})$}", repo.SetEditorconfigIfExists, repo.SetDiffViewStyle, repo.SetWhitespaceBehavior, repo.Diff)
+			m.Get("/commit/{sha:([a-f0-9]{7,40})$}/load-branches-and-tags", repo.LoadBranchesAndTags)
 			m.Get("/cherry-pick/{sha:([a-f0-9]{7,40})$}", repo.SetEditorconfigIfExists, repo.CherryPick)
 		}, repo.MustBeNotEmpty, context.RepoRef(), reqRepoCodeReader)
 
diff --git a/services/repository/commit.go b/services/repository/commit.go
new file mode 100644
index 0000000000..2497910a83
--- /dev/null
+++ b/services/repository/commit.go
@@ -0,0 +1,55 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package repository
+
+import (
+	"context"
+	"fmt"
+
+	gitea_ctx "code.gitea.io/gitea/modules/context"
+	"code.gitea.io/gitea/modules/util"
+)
+
+type ContainedLinks struct { // TODO: better name?
+	Branches      []*namedLink `json:"branches"`
+	Tags          []*namedLink `json:"tags"`
+	DefaultBranch string       `json:"default_branch"`
+}
+
+type namedLink struct { // TODO: better name?
+	Name    string `json:"name"`
+	WebLink string `json:"web_link"`
+}
+
+// LoadBranchesAndTags creates a new repository branch
+func LoadBranchesAndTags(ctx context.Context, baseRepo *gitea_ctx.Repository, commitSHA string) (*ContainedLinks, error) {
+	containedTags, err := baseRepo.GitRepo.ListOccurrences(ctx, "tag", commitSHA)
+	if err != nil {
+		return nil, fmt.Errorf("encountered a problem while querying %s: %w", "tags", err)
+	}
+	containedBranches, err := baseRepo.GitRepo.ListOccurrences(ctx, "branch", commitSHA)
+	if err != nil {
+		return nil, fmt.Errorf("encountered a problem while querying %s: %w", "branches", err)
+	}
+
+	result := &ContainedLinks{
+		DefaultBranch: baseRepo.Repository.DefaultBranch,
+		Branches:      make([]*namedLink, 0, len(containedBranches)),
+		Tags:          make([]*namedLink, 0, len(containedTags)),
+	}
+	for _, tag := range containedTags {
+		// TODO: Use a common method to get the link to a branch/tag instead of hard-coding it here
+		result.Tags = append(result.Tags, &namedLink{
+			Name:    tag,
+			WebLink: fmt.Sprintf("%s/src/tag/%s", baseRepo.RepoLink, util.PathEscapeSegments(tag)),
+		})
+	}
+	for _, branch := range containedBranches {
+		result.Branches = append(result.Branches, &namedLink{
+			Name:    branch,
+			WebLink: fmt.Sprintf("%s/src/branch/%s", baseRepo.RepoLink, util.PathEscapeSegments(branch)),
+		})
+	}
+	return result, nil
+}
diff --git a/templates/repo/commit_load_branches_and_tags.tmpl b/templates/repo/commit_load_branches_and_tags.tmpl
new file mode 100644
index 0000000000..c19aa55c56
--- /dev/null
+++ b/templates/repo/commit_load_branches_and_tags.tmpl
@@ -0,0 +1,18 @@
+<div class="branch-and-tag-area" data-text-default-branch-tooltip="{{.locale.Tr "repo.commit.contained_in_default_branch"}}">
+	<button class="ui button ellipsis-button load-branches-and-tags gt-mt-3" aria-expanded="false"
+		data-fetch-url="{{.RepoLink}}/commit/{{.CommitID}}/load-branches-and-tags"
+		data-tooltip-content="{{.locale.Tr "repo.commit.load_referencing_branches_and_tags"}}"
+	>...</button>
+	<div class="branch-and-tag-detail gt-hidden">
+		<div class="divider"></div>
+		<div>{{.locale.Tr "repo.commit.contained_in"}}</div>
+		<div class="gt-df gt-mt-3">
+			<div class="gt-p-2">{{svg "octicon-git-branch"}}</div>
+			<div class="branch-area flex-text-block gt-f1"></div>
+		</div>
+		<div class="gt-df gt-mt-3">
+			<div class="gt-p-2">{{svg "octicon-tag"}}</div>
+			<div class="tag-area flex-text-block gt-f1"></div>
+		</div>
+	</div>
+</div>
diff --git a/templates/repo/commit_page.tmpl b/templates/repo/commit_page.tmpl
index e4aad30fa7..bd33a30443 100644
--- a/templates/repo/commit_page.tmpl
+++ b/templates/repo/commit_page.tmpl
@@ -137,12 +137,7 @@
 			{{if IsMultilineCommitMessage .Commit.Message}}
 				<pre class="commit-body gt-mt-0">{{RenderCommitBody $.Context .Commit.Message $.RepoLink $.Repository.ComposeMetas}}</pre>
 			{{end}}
-			{{if .BranchName}}
-				<span class="text grey gt-mr-3">{{svg "octicon-git-branch" 16 "gt-mr-2"}}{{.BranchName}}</span>
-			{{end}}
-			{{if .TagName}}
-				<span class="text grey gt-mr-3">{{svg "octicon-tag" 16 "gt-mr-2"}}{{.TagName}}</span>
-			{{end}}
+			{{template "repo/commit_load_branches_and_tags" .}}
 		</div>
 		<div class="ui attached segment gt-df gt-ac gt-sb gt-py-2 commit-header-row gt-fw {{$class}}">
 				<div class="gt-df gt-ac author">
diff --git a/templates/repo/commits_list.tmpl b/templates/repo/commits_list.tmpl
index 6768bcb513..ef9d065456 100644
--- a/templates/repo/commits_list.tmpl
+++ b/templates/repo/commits_list.tmpl
@@ -70,7 +70,7 @@
 							{{end}}
 							</span>
 							{{if IsMultilineCommitMessage .Message}}
-							<button class="ui button ellipsis-button" aria-expanded="false">...</button>
+							<button class="ui button js-toggle-commit-body ellipsis-button" aria-expanded="false">...</button>
 							{{end}}
 							{{template "repo/commit_statuses" dict "Status" .Status "Statuses" .Statuses "root" $}}
 							{{if IsMultilineCommitMessage .Message}}
diff --git a/templates/repo/commits_list_small.tmpl b/templates/repo/commits_list_small.tmpl
index 6bbc19529f..57c9fd17ef 100644
--- a/templates/repo/commits_list_small.tmpl
+++ b/templates/repo/commits_list_small.tmpl
@@ -40,7 +40,7 @@
 
 		<span class="gt-mono commit-summary {{if gt .ParentCount 1}} grey text{{end}}" title="{{.Summary}}">{{RenderCommitMessageLinkSubject $.root.Context .Message ($.comment.Issue.PullRequest.BaseRepo.Link|Escape) $commitLink $.comment.Issue.PullRequest.BaseRepo.ComposeMetas}}</span>
 		{{if IsMultilineCommitMessage .Message}}
-			<button class="ui button ellipsis-button" aria-expanded="false">...</button>
+			<button class="ui button js-toggle-commit-body ellipsis-button" aria-expanded="false">...</button>
 		{{end}}
 		{{if IsMultilineCommitMessage .Message}}
 			<pre class="commit-body gt-hidden">{{RenderCommitBody $.root.Context .Message ($.comment.Issue.PullRequest.BaseRepo.Link|Escape) $.comment.Issue.PullRequest.BaseRepo.ComposeMetas}}</pre>
diff --git a/templates/repo/view_list.tmpl b/templates/repo/view_list.tmpl
index 13b4d3d3d3..3eabf9f181 100644
--- a/templates/repo/view_list.tmpl
+++ b/templates/repo/view_list.tmpl
@@ -28,7 +28,7 @@
 					{{$commitLink:= printf "%s/commit/%s" .RepoLink (PathEscape .LatestCommit.ID.String)}}
 					<span class="grey commit-summary" title="{{.LatestCommit.Summary}}"><span class="message-wrapper">{{RenderCommitMessageLinkSubject $.Context .LatestCommit.Message $.RepoLink $commitLink $.Repository.ComposeMetas}}</span>
 						{{if IsMultilineCommitMessage .LatestCommit.Message}}
-							<button class="ui button ellipsis-button" aria-expanded="false">...</button>
+							<button class="ui button js-toggle-commit-body ellipsis-button" aria-expanded="false">...</button>
 							<pre class="commit-body gt-hidden">{{RenderCommitBody $.Context .LatestCommit.Message $.RepoLink $.Repository.ComposeMetas}}</pre>
 						{{end}}
 					</span>
diff --git a/web_src/js/features/repo-commit.js b/web_src/js/features/repo-commit.js
index 7e4e40806b..7240bf398a 100644
--- a/web_src/js/features/repo-commit.js
+++ b/web_src/js/features/repo-commit.js
@@ -5,7 +5,7 @@ import {toggleElem} from '../utils/dom.js';
 const {csrfToken} = window.config;
 
 export function initRepoEllipsisButton() {
-  $('.ellipsis-button').on('click', function (e) {
+  $('.js-toggle-commit-body').on('click', function (e) {
     e.preventDefault();
     const expanded = $(this).attr('aria-expanded') === 'true';
     toggleElem($(this).parent().find('.commit-body'));
diff --git a/web_src/js/features/repo-diff-commit.js b/web_src/js/features/repo-diff-commit.js
new file mode 100644
index 0000000000..968f318e63
--- /dev/null
+++ b/web_src/js/features/repo-diff-commit.js
@@ -0,0 +1,52 @@
+import {hideElem, showElem, toggleElem} from '../utils/dom.js';
+
+async function loadBranchesAndTags(area, loadingButton) {
+  loadingButton.classList.add('disabled');
+  try {
+    const res = await fetch(loadingButton.getAttribute('data-fetch-url'));
+    const data = await res.json();
+    hideElem(loadingButton);
+    addTags(area, data.tags);
+    addBranches(area, data.branches, data.default_branch);
+    showElem(area.querySelectorAll('.branch-and-tag-detail'));
+  } finally {
+    loadingButton.classList.remove('disabled');
+  }
+}
+
+function addTags(area, tags) {
+  const tagArea = area.querySelector('.tag-area');
+  toggleElem(tagArea, tags.length > 0);
+  for (const tag of tags) {
+    addLink(tagArea, tag.web_link, tag.name);
+  }
+}
+
+function addBranches(area, branches, defaultBranch) {
+  const defaultBranchTooltip = area.getAttribute('data-text-default-branch-tooltip');
+  const branchArea = area.querySelector('.branch-area');
+  toggleElem(branchArea, branches.length > 0);
+  for (const branch of branches) {
+    const tooltip = defaultBranch === branch.name ? defaultBranchTooltip : null;
+    addLink(branchArea, branch.web_link, branch.name, tooltip);
+  }
+}
+
+function addLink(parent, href, text, tooltip) {
+  const link = document.createElement('a');
+  link.classList.add('muted', 'gt-px-2');
+  link.href = href;
+  link.textContent = text;
+  if (tooltip) {
+    link.classList.add('gt-border-secondary', 'gt-rounded');
+    link.setAttribute('data-tooltip-content', tooltip);
+  }
+  parent.append(link);
+}
+
+export function initRepoDiffCommitBranchesAndTags() {
+  for (const area of document.querySelectorAll('.branch-and-tag-area')) {
+    const btn = area.querySelector('.load-branches-and-tags');
+    btn.addEventListener('click', () => loadBranchesAndTags(area, btn));
+  }
+}
diff --git a/web_src/js/features/repo-legacy.js b/web_src/js/features/repo-legacy.js
index f23ff45470..5991df6322 100644
--- a/web_src/js/features/repo-legacy.js
+++ b/web_src/js/features/repo-legacy.js
@@ -459,7 +459,7 @@ async function onEditContent(event) {
 }
 
 export function initRepository() {
-  if ($('.repository').length === 0) {
+  if ($('.page-content.repository').length === 0) {
     return;
   }
 
diff --git a/web_src/js/index.js b/web_src/js/index.js
index 0c786f96fb..8bd219bbe1 100644
--- a/web_src/js/index.js
+++ b/web_src/js/index.js
@@ -83,6 +83,7 @@ import {initGiteaFomantic} from './modules/fomantic.js';
 import {onDomReady} from './utils/dom.js';
 import {initRepoIssueList} from './features/repo-issue-list.js';
 import {initCommonIssueListQuickGoto} from './features/common-issue-list.js';
+import {initRepoDiffCommitBranchesAndTags} from './features/repo-diff-commit.js';
 
 // Init Gitea's Fomantic settings
 initGiteaFomantic();
@@ -141,6 +142,7 @@ onDomReady(() => {
   initRepoCodeView();
   initRepoCommentForm();
   initRepoEllipsisButton();
+  initRepoDiffCommitBranchesAndTags();
   initRepoCommitLastCommitLoader();
   initRepoEditor();
   initRepoGraphGit();