fix: Remove "create branch" button on mirrored repos (#7640)

Currently, if you have a mirrored repo, the button on the "branches"
page to create a new branch is available to be pressed. Once you name
your new branch and click submit, you get a 404 page that doesn't explain
what went wrong.

As new branch creation is not supported on mirrored repos, let's just
take that button away if the repo is a mirror. This is already done for
archived repos, so we just need to add another check.

Fixes #7639.

Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/7640
Reviewed-by: Otto <otto@codeberg.org>
Co-authored-by: John Moon <john.moon@vts-i.com>
Co-committed-by: John Moon <john.moon@vts-i.com>

models/fixtures/repository.yml

@@ -132,6 +132,7 @@
   owner_name: org3
   lower_name: repo5
   name: repo5
+  default_branch: master
   num_watches: 0
   num_stars: 0
   num_forks: 0

templates/repo/branch/list.tmpl

@@ -30,7 +30,7 @@
 								<p class="info tw-flex tw-items-center tw-my-1">{{svg "octicon-git-commit" 16 "tw-mr-1"}}<a href="{{.RepoLink}}/commit/{{PathEscape .DefaultBranchBranch.DBBranch.CommitID}}">{{ShortSha .DefaultBranchBranch.DBBranch.CommitID}}</a> · <span class="commit-message">{{RenderCommitMessage $.Context .DefaultBranchBranch.DBBranch.CommitMessage (.Repository.ComposeMetas ctx)}}</span> · {{ctx.Locale.Tr "org.repo_updated" (DateUtils.TimeSince .DefaultBranchBranch.DBBranch.CommitTime)}}{{if .DefaultBranchBranch.DBBranch.Pusher}} &nbsp;{{template "shared/user/avatarlink" dict "user" .DefaultBranchBranch.DBBranch.Pusher}}{{template "shared/user/namelink" .DefaultBranchBranch.DBBranch.Pusher}}{{end}}</p>
 							</td>
 							<td class="right aligned middle aligned overflow-visible">
-								{{if and $.IsWriter (not $.Repository.IsArchived) (not .IsDeleted)}}
+								{{if and $.IsWriter (not $.Repository.IsArchived) (not $.Repository.IsMirror) (not .IsDeleted)}}
 									<button class="btn interact-bg show-create-branch-modal tw-p-2"
 										data-modal="#create-branch-modal"
 										data-branch-from="{{$.DefaultBranchBranch.DBBranch.Name}}"
@@ -151,7 +151,7 @@
 								{{end}}
 							</td>
 							<td class="three wide right aligned overflow-visible">
-								{{if and $.IsWriter (not $.Repository.IsArchived) (not .DBBranch.IsDeleted)}}
+								{{if and $.IsWriter (not $.Repository.IsArchived) (not $.Repository.IsMirror) (not .DBBranch.IsDeleted)}}
 									<button class="btn interact-bg tw-p-2 show-modal show-create-branch-modal"
 										data-branch-from="{{.DBBranch.Name}}"
 										data-branch-from-urlcomponent="{{PathEscapeSegments .DBBranch.Name}}"

tests/integration/repo_branch_test.go

@@ -204,3 +204,28 @@ func TestDatabaseMissingABranch(t *testing.T) {
 		assert.Equal(t, firstBranchCount-1, secondBranchCount)
 	})
 }
+
+func TestCreateBranchButtonVisibility(t *testing.T) {
+	onGiteaRun(t, func(t *testing.T, u *url.URL) {
+		session := loginUser(t, "user1")
+
+		t.Run("Check create branch button", func(t *testing.T) {
+			t.Run("Normal repository", func(t *testing.T) {
+				repo1 := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: 1})
+
+				// Check that the button is present
+				resp := session.MakeRequest(t, NewRequest(t, "GET", "/"+repo1.FullName()+"/branches"), http.StatusOK)
+				htmlDoc := NewHTMLParser(t, resp.Body)
+				assert.Positive(t, htmlDoc.doc.Find(".show-create-branch-modal").Length())
+			})
+			t.Run("Mirrored repository", func(t *testing.T) {
+				repo5 := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: 5})
+
+				// Check that the button is NOT present
+				resp := session.MakeRequest(t, NewRequest(t, "GET", "/"+repo5.FullName()+"/branches"), http.StatusOK)
+				htmlDoc := NewHTMLParser(t, resp.Body)
+				assert.Equal(t, 0, htmlDoc.doc.Find(".show-create-branch-modal").Length())
+			})
+		})
+	})
+}