[GITEA] Detect file rename and show in history

- Add a indication to the file history if the file has been renamed,
this indication contains a link to browse the history of the file
further.
- Added unit testing.
- Added integration testing.
- Resolves https://codeberg.org/forgejo/forgejo/issues/1279

(cherry picked from commit 72c297521b1830360aab4b50e37efcc7e67e0d5d)
(cherry picked from commit 283f9648947f8dd2f315ecca19566ccca2b49c18)

Conflicts:
	options/locale/locale_en-US.ini
	https://codeberg.org/forgejo/forgejo/pulls/1550
(cherry picked from commit 7c30af7fdee08efd02041c01abca47394a69bb8b)
(cherry picked from commit f3be6eb269526a9f4ea7861189f07977f2d4a32f)
(cherry picked from commit 78e1755b94c18c043e0c8f8c2849803cc8069feb)
(cherry picked from commit 9f30b92009e8911c99412944bcd7cff55a7b98dc)
(cherry picked from commit bb694684a4045150924c15aa5647e8e112321f02)
(cherry picked from commit 721f0ccf3ea7196dbb877a6c159d23d05c37978b)

modules/git/commit.go

@@ -509,6 +509,62 @@ func GetCommitFileStatus(ctx context.Context, repoPath, commitID string) (*Commi
 	return fileStatus, nil
 }
 
+func parseCommitRenames(renames *[][2]string, stdout io.Reader) {
+	rd := bufio.NewReader(stdout)
+	for {
+		// Skip (R || three digits || NULL byte)
+		_, err := rd.Discard(5)
+		if err != nil {
+			if err != io.EOF {
+				log.Error("Unexpected error whilst reading from git log --name-status. Error: %v", err)
+			}
+			return
+		}
+		oldFileName, err := rd.ReadString('\x00')
+		if err != nil {
+			if err != io.EOF {
+				log.Error("Unexpected error whilst reading from git log --name-status. Error: %v", err)
+			}
+			return
+		}
+		newFileName, err := rd.ReadString('\x00')
+		if err != nil {
+			if err != io.EOF {
+				log.Error("Unexpected error whilst reading from git log --name-status. Error: %v", err)
+			}
+			return
+		}
+		oldFileName = strings.TrimSuffix(oldFileName, "\x00")
+		newFileName = strings.TrimSuffix(newFileName, "\x00")
+		*renames = append(*renames, [2]string{oldFileName, newFileName})
+	}
+}
+
+// GetCommitFileRenames returns the renames that the commit contains.
+func GetCommitFileRenames(ctx context.Context, repoPath, commitID string) ([][2]string, error) {
+	renames := [][2]string{}
+	stdout, w := io.Pipe()
+	done := make(chan struct{})
+	go func() {
+		parseCommitRenames(&renames, stdout)
+		close(done)
+	}()
+
+	stderr := new(bytes.Buffer)
+	err := NewCommand(ctx, "show", "--name-status", "--pretty=format:", "-z", "--diff-filter=R").AddDynamicArguments(commitID).Run(&RunOpts{
+		Dir:    repoPath,
+		Stdout: w,
+		Stderr: stderr,
+	})
+	w.Close() // Close writer to exit parsing goroutine
+	if err != nil {
+		return nil, ConcatenateError(err, stderr.String())
+	}
+
+	<-done
+	return renames, nil
+}
+
 // GetFullCommitID returns full length (40) of commit ID by given short SHA in a repository.
 func GetFullCommitID(ctx context.Context, repoPath, shortID string) (string, error) {
 	commitID, _, err := NewCommand(ctx, "rev-parse").AddDynamicArguments(shortID).RunStdString(&RunOpts{Dir: repoPath})

modules/git/commit_test.go

@@ -278,3 +278,30 @@ func TestGetCommitFileStatusMerges(t *testing.T) {
 	assert.Equal(t, commitFileStatus.Removed, expected.Removed)
 	assert.Equal(t, commitFileStatus.Modified, expected.Modified)
 }
+
+func TestParseCommitRenames(t *testing.T) {
+	testcases := []struct {
+		output  string
+		renames [][2]string
+	}{
+		{
+			output:  "R090\x00renamed.txt\x00history.txt\x00",
+			renames: [][2]string{{"renamed.txt", "history.txt"}},
+		},
+		{
+			output:  "R090\x00renamed.txt\x00history.txt\x00R000\x00corruptedstdouthere",
+			renames: [][2]string{{"renamed.txt", "history.txt"}},
+		},
+		{
+			output:  "R100\x00renamed.txt\x00history.txt\x00R001\x00readme.md\x00README.md\x00",
+			renames: [][2]string{{"renamed.txt", "history.txt"}, {"readme.md", "README.md"}},
+		},
+	}
+
+	for _, testcase := range testcases {
+		renames := [][2]string{}
+		parseCommitRenames(&renames, strings.NewReader(testcase.output))
+
+		assert.Equal(t, testcase.renames, renames)
+	}
+}

options/locale/locale_en-US.ini

@@ -1277,6 +1277,8 @@ commits.find = Search
 commits.search_all = All Branches
 commits.author = Author
 commits.message = Message
+commits.browse_further = Browse further
+commits.renamed_from = Renamed from %s
 commits.date = Date
 commits.older = Older
 commits.newer = Newer

routers/web/repo/commit.go

@@ -239,6 +239,22 @@ func FileHistory(ctx *context.Context) {
 		ctx.ServerError("CommitsByFileAndRange", err)
 		return
 	}
+	oldestCommit := commits[len(commits)-1]
+
+	renamedFiles, err := git.GetCommitFileRenames(ctx, ctx.Repo.GitRepo.Path, oldestCommit.ID.String())
+	if err != nil {
+		ctx.ServerError("GetCommitFileRenames", err)
+		return
+	}
+
+	for _, renames := range renamedFiles {
+		if renames[1] == fileName {
+			ctx.Data["OldFilename"] = renames[0]
+			ctx.Data["OldFilenameHistory"] = fmt.Sprintf("%s/commits/commit/%s/%s", ctx.Repo.RepoLink, oldestCommit.ID.String(), renames[0])
+			break
+		}
+	}
+
 	ctx.Data["Commits"] = git_model.ConvertFromGitCommit(ctx, commits, ctx.Repo.Repository)
 
 	ctx.Data["Username"] = ctx.Repo.Owner.Name

templates/repo/commits.tmpl

@@ -13,6 +13,11 @@
 			</div>
 		</div>
 		{{template "repo/commits_table" .}}
+		{{if .OldFilename}}
+			<div class="ui bottom attached header">
+				<span>{{.locale.Tr "repo.commits.renamed_from" .OldFilename}} (<a href="{{.OldFilenameHistory}}">{{.locale.Tr "repo.commits.browse_further"}}</a>)</span>
+			</div>
+		{{end}}
 	</div>
 </div>
 {{template "base/footer" .}}

tests/gitea-repositories-meta/user2/repo59.git/objects/info/packs

@@ -0,0 +1,2 @@
+P pack-6dd3a6fe138f1d77e14c2e6b8e6c41e5ae242adf.pack
+

tests/gitea-repositories-meta/user2/repo59.git/packed-refs

@@ -1,3 +1,4 @@
 # pack-refs with: peeled fully-peeled sorted 
-d8f53dfb33f6ccf4169c34970b5e747511c18beb refs/heads/master
+d8f53dfb33f6ccf4169c34970b5e747511c18beb refs/heads/cake-recipe
+80b83c5c8220c3aa3906e081f202a2a7563ec879 refs/heads/master
 d8f53dfb33f6ccf4169c34970b5e747511c18beb refs/tags/v1.0

tests/gitea-repositories-meta/user2/repo59.git/refs/heads/cake-recipe

@@ -1 +0,0 @@
-d8f53dfb33f6ccf4169c34970b5e747511c18beb

tests/integration/repo_test.go

@@ -690,3 +690,33 @@ func TestDangerZoneConfirmation(t *testing.T) {
 		})
 	})
 }
+
+func TestRenamedFileHistory(t *testing.T) {
+	defer tests.PrepareTestEnv(t)()
+
+	t.Run("Renamed file", func(t *testing.T) {
+		defer tests.PrintCurrentTest(t)()
+
+		req := NewRequest(t, "GET", "/user2/repo59/commits/branch/master/license")
+		resp := MakeRequest(t, req, http.StatusOK)
+
+		htmlDoc := NewHTMLParser(t, resp.Body)
+
+		renameNotice := htmlDoc.doc.Find(".ui.bottom.attached.header")
+		assert.Equal(t, 1, renameNotice.Length())
+		assert.Contains(t, renameNotice.Text(), "Renamed from licnse (Browse further)")
+
+		oldFileHistoryLink, ok := renameNotice.Find("a").Attr("href")
+		assert.True(t, ok)
+		assert.Equal(t, "/user2/repo59/commits/commit/80b83c5c8220c3aa3906e081f202a2a7563ec879/licnse", oldFileHistoryLink)
+	})
+
+	t.Run("Non renamed file", func(t *testing.T) {
+		req := NewRequest(t, "GET", "/user2/repo59/commits/branch/master/README.md")
+		resp := MakeRequest(t, req, http.StatusOK)
+
+		htmlDoc := NewHTMLParser(t, resp.Body)
+
+		htmlDoc.AssertElement(t, ".ui.bottom.attached.header", false)
+	})
+}