[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 72c297521b)
(cherry picked from commit 283f964894)

Conflicts:
	options/locale/locale_en-US.ini
	https://codeberg.org/forgejo/forgejo/pulls/1550
(cherry picked from commit 7c30af7fde)
(cherry picked from commit f3be6eb269)
(cherry picked from commit 78e1755b94)
(cherry picked from commit 73799479e0)
(cherry picked from commit 938359b941)
(cherry picked from commit b168a9c081)

[GITEA] Detect file rename and show in history (squash) ctx.Locale

(cherry picked from commit 40447752ff)
(cherry picked from commit ea23594cdb)
(cherry picked from commit cdc473850c)
(cherry picked from commit 86e6641c29)
(cherry picked from commit 2757de586b)
(cherry picked from commit def4ae32dd)
(cherry picked from commit 6dada09329)
(cherry picked from commit 5d6d527251)

Conflicts:
	tests/integration/repo_test.go
	https://codeberg.org/forgejo/forgejo/pulls/2119
(cherry picked from commit d3c1bce7db)
(cherry picked from commit 04bcb22d5c)

modules/git/commit.go

@@ -515,6 +515,62 @@ 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})