Display head branch more comfortable on pull request view (go-gitea#32000)

This PR do some minor improvements for head branch display on pull
request view UI.

- [x] Remove the link if the head branch has been deleted with a
tooltip, so that users will not result in a 404 page
- [x] Display a label if this pull request is an agit based one.

![图片](https://github.com/user-attachments/assets/872f26b6-f1cf-4427-9e41-e3a5b176dfa4)

Author: lunny

models/issues/pull.go

@@ -268,6 +268,10 @@ func (pr *PullRequest) LoadAttributes(ctx context.Context) (err error) {
 	return nil
 }
 
+func (pr *PullRequest) IsAgitFlow() bool {
+	return pr.Flow == PullRequestFlowAGit
+}
+
 // LoadHeadRepo loads the head repository, pr.HeadRepo will remain nil if it does not exist
 // and thus ErrRepoNotExist will never be returned
 func (pr *PullRequest) LoadHeadRepo(ctx context.Context) (err error) {

options/locale/locale_en-US.ini

@@ -1927,6 +1927,7 @@ pulls.delete.text = Do you really want to delete this pull request? (This will p
 pulls.recently_pushed_new_branches = You pushed on branch <strong>%[1]s</strong> %[2]s
 
 pull.deleted_branch = (deleted):%s
+pull.agit_documentation = Review documentation about AGit
 
 comments.edit.already_changed = Unable to save changes to the comment. It appears the content has already been changed by another user. Please refresh the page and try editing again to avoid overwriting their changes
 

routers/web/repo/pull.go

@@ -164,7 +164,19 @@ func setMergeTarget(ctx *context.Context, pull *issues_model.PullRequest) {
 		ctx.Data["HeadTarget"] = pull.MustHeadUserName(ctx) + "/" + pull.HeadRepo.Name + ":" + pull.HeadBranch
 	}
 	ctx.Data["BaseTarget"] = pull.BaseBranch
-	ctx.Data["HeadBranchLink"] = pull.GetHeadBranchLink(ctx)
+	headBranchLink := ""
+	if pull.Flow == issues_model.PullRequestFlowGithub {
+		b, err := git_model.GetBranch(ctx, ctx.Repo.Repository.ID, pull.HeadBranch)
+		switch {
+		case err == nil:
+			if !b.IsDeleted {
+				headBranchLink = pull.GetHeadBranchLink(ctx)
+			}
+		case !git_model.IsErrBranchNotExist(err):
+			log.Error("GetBranch: %v", err)
+		}
+	}
+	ctx.Data["HeadBranchLink"] = headBranchLink
 	ctx.Data["BaseBranchLink"] = pull.GetBaseBranchLink(ctx)
 }
 

templates/repo/issue/view_title.tmpl

@@ -50,9 +50,14 @@
 			{{if .Issue.IsPull}}
 				{{$headHref := .HeadTarget}}
 				{{if .HeadBranchLink}}
-					{{$headHref = HTMLFormat `<a href="%s">%s</a>` .HeadBranchLink $headHref}}
+					{{$headHref = HTMLFormat `<a href="%s">%s</a> <button class="btn interact-fg" data-tooltip-content="%s" data-clipboard-text="%s">%s</button>` .HeadBranchLink $headHref (ctx.Locale.Tr "copy_branch") .HeadTarget (svg "octicon-copy" 14)}}
+				{{else}}
+					{{if .Issue.PullRequest.IsAgitFlow}}
+						{{$headHref = HTMLFormat `%s <a href="%s" target="_blank"><span class="ui label basic tiny" data-tooltip-content="%s">AGit</span></a>` $headHref "https://docs.gitea.com/usage/agit" (ctx.Locale.Tr "repo.pull.agit_documentation")}}
+					{{else}}
+						{{$headHref = HTMLFormat `<span data-tooltip-content="%s">%s</span>` (ctx.Locale.Tr "form.target_branch_not_exist") $headHref}}
+					{{end}}
 				{{end}}
-				{{$headHref = HTMLFormat `%s <button class="btn interact-fg" data-tooltip-content="%s" data-clipboard-text="%s">%s</button>` $headHref (ctx.Locale.Tr "copy_branch") .HeadTarget (svg "octicon-copy" 14)}}
 				{{$baseHref := .BaseTarget}}
 				{{if .BaseBranchLink}}
 					{{$baseHref = HTMLFormat `<a href="%s">%s</a>` .BaseBranchLink $baseHref}}