Support getting changed files when commit ID is EmptySHA

modules/git/commit.go

@@ -302,9 +302,17 @@ func (c *Commit) SearchCommits(opts SearchCommitsOptions) ([]*Commit, error) {
 
 // GetFilesChangedSinceCommit get all changed file names between pastCommit to current revision
 func (c *Commit) GetFilesChangedSinceCommit(pastCommit string) ([]string, error) {
+	if pastCommit == EmptySHA {
+		return c.GetFilesChanged()
+	}
 	return c.repo.GetFilesChangedBetween(pastCommit, c.ID.String())
 }
 
+// GetFilesChanged get the changed file names of the commit
+func (c *Commit) GetFilesChanged() ([]string, error) {
+	return c.repo.GetCommitFilesChanged(c.ID.String())
+}
+
 // FileChangedSinceCommit Returns true if the file given has changed since the the past commit
 // YOU MUST ENSURE THAT pastCommit is a valid commit ID.
 func (c *Commit) FileChangedSinceCommit(filename, pastCommit string) (bool, error) {

modules/git/repo_compare.go

@@ -295,6 +295,37 @@ func (repo *Repository) GetFilesChangedBetween(base, head string) ([]string, err
 	return split, err
 }
 
+// GetCommitFilesChanged get the changed file names of the specified commit
+func (repo *Repository) GetCommitFilesChanged(commitID string) ([]string, error) {
+	id, err := repo.ConvertToSHA1(commitID)
+	if err != nil {
+		return nil, err
+	}
+	commit, err := repo.getCommit(id)
+	if err != nil {
+		return nil, err
+	}
+	var stdout string
+	if len(commit.Parents) == 0 {
+		// if the commit is the root commit, diff-tree cannot show the changed files
+		// we need to use ls-tree in this case
+		stdout, _, err = NewCommand(repo.Ctx, "ls-tree", "--name-only", "-r").AddDynamicArguments(commitID).RunStdString(&RunOpts{Dir: repo.Path})
+	} else {
+		stdout, _, err = NewCommand(repo.Ctx, "diff-tree", "--no-commit-id", "--name-only", "-r").AddDynamicArguments(commitID).RunStdString(&RunOpts{Dir: repo.Path})
+	}
+	if err != nil {
+		return nil, err
+	}
+	split := strings.Split(stdout, "\n")
+
+	// Because Git will always emit filenames with a terminal NUL ignore the last entry in the split - which will always be empty.
+	if len(split) > 0 {
+		split = split[:len(split)-1]
+	}
+
+	return split, err
+}
+
 // GetDiffFromMergeBase generates and return patch data from merge base to head
 func (repo *Repository) GetDiffFromMergeBase(base, head string, w io.Writer) error {
 	stderr := new(bytes.Buffer)

modules/git/repo_compare_test.go

@@ -119,3 +119,38 @@ func TestReadWritePullHead(t *testing.T) {
 	err = repo.RemoveReference(PullPrefix + "1/head")
 	assert.NoError(t, err)
 }
+
+func TestGetCommitFilesChanged(t *testing.T) {
+	bareRepo1Path := filepath.Join(testReposDir, "repo1_bare")
+	clonedPath, err := cloneRepo(t, bareRepo1Path)
+	if err != nil {
+		assert.NoError(t, err)
+		return
+	}
+	repo, err := openRepositoryWithDefaultContext(clonedPath)
+	if err != nil {
+		assert.NoError(t, err)
+		return
+	}
+	defer repo.Close()
+
+	testCases := []struct {
+		CommitID      string
+		ExpectedFiles []string
+	}{
+		{
+			"95bb4d39648ee7e325106df01a621c530863a653",
+			[]string{"file1.txt"},
+		},
+		{
+			"8d92fc957a4d7cfd98bc375f0b7bb189a0d6c9f2",
+			[]string{"file2.txt"},
+		},
+	}
+
+	for _, tc := range testCases {
+		changedFiles, err := repo.GetCommitFilesChanged(tc.CommitID)
+		assert.NoError(t, err)
+		assert.ElementsMatch(t, changedFiles, tc.ExpectedFiles)
+	}
+}