[UI] Agit: Add AGit label to AGit-created PRs

Adds a label to Pull Requests that were created using AGit-Flow,
in order to prevent situations where a contributor uses AGit-Flow
to push new changes - only to realize that they did not use AGit-Flow
in the first place, and that they just opened a new PR accidentally
(that was me).

Also intended to raise general awareness about the feature. Some
additional work, such as adding a tooltip, still needs to be
done.

A small typo fix for a comment and (exclusively) formatting fixes
in the copyright header are also included.

Refs: https://codeberg.org/forgejo/forgejo/issues/2433

4 files changed, 43 insertions, 4 deletions

diff --git a/options/locale/locale_en-US.ini b/options/locale/locale_en-US.ini
index bdae9a29ac..8253c6ced5 100644
--- a/options/locale/locale_en-US.ini
+++ b/options/locale/locale_en-US.ini
@@ -1505,6 +1505,7 @@ issues.action_check_all = Check/Uncheck all items
 issues.opened_by = opened %[1]s by <a href="%[2]s">%[3]s</a>
 pulls.merged_by = by <a href="%[2]s">%[3]s</a> was merged %[1]s
 pulls.merged_by_fake = by %[2]s was merged %[1]s
+pulls.made_using_agit = AGit
 issues.closed_by = by <a href="%[2]s">%[3]s</a> was closed %[1]s
 issues.opened_by_fake = opened %[1]s by %[2]s
 issues.closed_by_fake = by %[2]s was closed %[1]s
diff --git a/routers/web/repo/pull.go b/routers/web/repo/pull.go
index ab821f8884..ac244b1551 100644
--- a/routers/web/repo/pull.go
+++ b/routers/web/repo/pull.go
@@ -1,5 +1,6 @@
-// Copyright 2018 The Gitea Authors.
-// Copyright 2014 The Gogs Authors.
+// Copyright 2014 The Gogs Authors. All rights reserved.
+// Copyright 2018 The Gitea Authors. All rights reserved.
+// Copyright 2024 The Forgejo Authors. All rights reserved.
 // All rights reserved.
 // SPDX-License-Identifier: MIT
 
@@ -381,6 +382,11 @@ func setMergeTarget(ctx *context.Context, pull *issues_model.PullRequest) {
 	} else {
 		ctx.Data["HeadTarget"] = pull.MustHeadUserName(ctx) + "/" + pull.HeadRepo.Name + ":" + pull.HeadBranch
 	}
+
+	if pull.Flow == issues_model.PullRequestFlowAGit {
+		ctx.Data["MadeUsingAGit"] = true
+	}
+
 	ctx.Data["BaseTarget"] = pull.BaseBranch
 	ctx.Data["HeadBranchLink"] = pull.GetHeadBranchLink(ctx)
 	ctx.Data["BaseBranchLink"] = pull.GetBaseBranchLink(ctx)
diff --git a/templates/repo/issue/view_title.tmpl b/templates/repo/issue/view_title.tmpl
index 582e9864fb..8a5954681b 100644
--- a/templates/repo/issue/view_title.tmpl
+++ b/templates/repo/issue/view_title.tmpl
@@ -47,7 +47,9 @@
 				{{if .HeadBranchLink}}
 					{{$headHref = printf `<a href="%s">%s</a>` (.HeadBranchLink | Escape) $headHref}}
 				{{end}}
-				{{$headHref = printf `%s <button class="btn interact-fg" data-tooltip-content="%s" data-clipboard-text="%s">%s</button>` $headHref (ctx.Locale.Tr "copy_branch") (.HeadTarget | Escape) (svg "octicon-copy" 14)}}
+				{{if not .MadeUsingAGit}}
+					{{$headHref = printf `%s <button class="btn interact-fg" data-tooltip-content="%s" data-clipboard-text="%s">%s</button>` $headHref (ctx.Locale.Tr "copy_branch") (.HeadTarget | Escape) (svg "octicon-copy" 14)}}
+				{{end}}
 				{{$baseHref := .BaseTarget|Escape}}
 				{{if .BaseBranchLink}}
 					{{$baseHref = printf `<a href="%s">%s</a>` (.BaseBranchLink | Escape) $baseHref}}
@@ -70,6 +72,12 @@
 							{{ctx.Locale.Tr "repo.pulls.title_desc" .NumCommits ($headHref|Safe) ($baseHref|Safe)}}
 						</span>
 					{{end}}
+					{{if .MadeUsingAGit}}
+						{{/* TODO: Add tooltip and a link to the documentation */}}
+						<span id="agit-label" class="ui small label">
+							{{ctx.Locale.Tr "repo.pulls.made_using_agit"}}
+						</span>
+					{{end}}
 					<span id="pull-desc-edit" class="gt-hidden flex-text-block">
 						<div class="ui floating filter dropdown">
 							<div class="ui basic small button gt-mr-0">
diff --git a/tests/integration/git_test.go b/tests/integration/git_test.go
index d02427ffcf..ead649490e 100644
--- a/tests/integration/git_test.go
+++ b/tests/integration/git_test.go
@@ -450,7 +450,7 @@ func doMergeFork(ctx, baseCtx APITestContext, baseBranch, headBranch string) fun
 		var pr api.PullRequest
 		var err error
 
-		// Create a test pullrequest
+		// Create a test pull request
 		t.Run("CreatePullRequest", func(t *testing.T) {
 			pr, err = doAPICreatePullRequest(ctx, baseCtx.Username, baseCtx.Reponame, baseBranch, headBranch)(t)
 			assert.NoError(t, err)
@@ -470,6 +470,19 @@ func doMergeFork(ctx, baseCtx APITestContext, baseBranch, headBranch string) fun
 		}
 		t.Run("EnsureCanSeePull", doEnsureCanSeePull(headCtx, pr, true))
 
+		// Confirm that there is no AGit Label
+		// TODO: Refactor and move this check to a function
+		t.Run("AGitLabelIsMissing", func(t *testing.T) {
+			defer tests.PrintCurrentTest(t)()
+
+			session := loginUser(t, ctx.Username)
+
+			req := NewRequest(t, "GET", fmt.Sprintf("/%s/%s/pulls/%d", baseCtx.Username, baseCtx.Reponame, pr.Index))
+			resp := session.MakeRequest(t, req, http.StatusOK)
+			htmlDoc := NewHTMLParser(t, resp.Body)
+			htmlDoc.AssertElement(t, "#agit-label", false)
+		})
+
 		// Then get the diff string
 		var diffHash string
 		var diffLength int
@@ -813,6 +826,17 @@ func doCreateAgitFlowPull(dstPath string, ctx *APITestContext, baseBranch, headB
 			return
 		}
 
+		t.Run("AGitLabelIsPresent", func(t *testing.T) {
+			defer tests.PrintCurrentTest(t)()
+
+			session := loginUser(t, ctx.Username)
+
+			req := NewRequest(t, "GET", fmt.Sprintf("/%s/%s/pulls/%d", url.PathEscape(ctx.Username), url.PathEscape(ctx.Reponame), pr2.Index))
+			resp := session.MakeRequest(t, req, http.StatusOK)
+			htmlDoc := NewHTMLParser(t, resp.Body)
+			htmlDoc.AssertElement(t, "#agit-label", true)
+		})
+
 		t.Run("AddCommit2", func(t *testing.T) {
 			err := os.WriteFile(path.Join(dstPath, "test_file"), []byte("## test content \n ## test content 2"), 0o666)
 			if !assert.NoError(t, err) {