Commit `5f3b0a7e1a`

5f3b0a7e1a6bd7aa2f3ef9cedf4db065f6a8b6c6

parent: 936ce1198d

Verified · cmc

cmc <hello@cleberg.net> · 2026-09-20 00:08 UTC

gitutil: commit-file writes the first commit of an empty repository

A branch that will not resolve is a root commit only when the repository
has no refs at all; elsewhere it stays the error it was.

Ref #236

internal/gitutil/commitfile_test.go added +38

		@@ -0,0 +1,38 @@
	1	package gitutil
	2
	3	import "testing"
	4
	5	func TestCommitFileChangeEmptyRepo(t *testing.T) {
	6	dir := t.TempDir()
	7	if err := InitBare(dir, "main", ""); err != nil {
	8	t.Fatal(err)
	9	}
	10	sha, err := CommitFileChange(dir, "main", "profile/README.md",
	11	[]byte("# hello\n"), "alice", "alice@example.org", "add about")
	12	if err != nil {
	13	t.Fatalf("first commit into an empty repository: %v", err)
	14	}
	15	if sha == "" {
	16	t.Fatal("no sha returned")
	17	}
	18	raw, err := ReadBlob(dir, "main", "profile/README.md", 1<<20)
	19	if err != nil {
	20	t.Fatalf("reading it back: %v", err)
	21	}
	22	if string(raw) != "# hello\n" {
	23	t.Errorf("read back %q", raw)
	24	}
	25
	26	// The second commit still takes the parented path.
	27	if _, err := CommitFileChange(dir, "main", "profile/README.md",
	28	[]byte("# hello again\n"), "alice", "alice@example.org", "edit"); err != nil {
	29	t.Fatalf("second commit: %v", err)
	30	}
	31
	32	// An unknown branch in a repository that has history is a typo, not a
	33	// new orphan branch.
	34	if _, err := CommitFileChange(dir, "nope", "x.md",
	35	[]byte("x"), "alice", "alice@example.org", "x"); err == nil {
	36	t.Error("committing to an unknown branch of a non-empty repository succeeded")
	37	}
	38	}

internal/gitutil/merge.go +24 −3

		@@ -189,7 +189,13 @@ func CommitFileChange(dir, branch, path string, content []byte, name, email, mes
189	189	branchRef := "refs/heads/" + branch
190	190	parent, err := ResolveRef(dir, branchRef)
191	191	if err != nil {
192		return "", fmt.Errorf("branch %s: %w", branch, err)
	192	// An unborn branch is a root commit only in a repository with no
	193	// refs at all. Anywhere else an unresolvable branch is a typo, and
	194	// starting an orphan branch for it would be worse than refusing.
	195	if !isEmptyRepo(dir) {
	196	return "", fmt.Errorf("branch %s: %w", branch, err)
	197	}
	198	parent = ""
193	199	}
194	200
195	201	// Hash the new blob.
		@@ -211,7 +217,11 @@ func CommitFileChange(dir, branch, path string, content []byte, name, email, mes
211	217	defer os.Remove(idx.Name())
212	218	env := append(os.Environ(), "GIT_INDEX_FILE="+idx.Name())
213	219
214		rt := exec.Command(toolpath.Look("git"), "-C", dir, "read-tree", parent+"^{tree}")
	220	tree0 := parent + "^{tree}"
	221	if parent == "" {
	222	tree0 = "--empty"
	223	}
	224	rt := exec.Command(toolpath.Look("git"), "-C", dir, "read-tree", tree0)
215	225	rt.Env = env
216	226	if out, err := rt.CombinedOutput(); err != nil {
217	227	return "", fmt.Errorf("read-tree: %v\n%s", err, out)
		@@ -229,7 +239,11 @@ func CommitFileChange(dir, branch, path string, content []byte, name, email, mes
229	239	}
230	240	tree := strings.TrimSpace(string(out))
231	241
232		sha, err := CommitTree(dir, tree, []string{parent}, name, email, message)
	242	var parents []string
	243	if parent != "" {
	244	parents = []string{parent}
	245	}
	246	sha, err := CommitTree(dir, tree, parents, name, email, message)
233	247	if err != nil {
234	248	return "", err
235	249	}
		@@ -239,6 +253,13 @@ func CommitFileChange(dir, branch, path string, content []byte, name, email, mes
239	253	return sha, nil
240	254	}
241	255
	256	// isEmptyRepo reports whether dir has no refs at all — a repository
	257	// created but never pushed to.
	258	func isEmptyRepo(dir string) bool {
	259	out, err := exec.Command(toolpath.Look("git"), "-C", dir, "rev-list", "-n1", "--all").Output()
	260	return err == nil && strings.TrimSpace(string(out)) == ""
	261	}
	262
242	263	// CommitParents returns the parent SHAs of a commit.
243	264	func CommitParents(dir, sha string) ([]string, error) {
244	265	out, err := exec.Command(toolpath.Look("git"), "-C", dir, "rev-list", "--parents", "-n1", "--end-of-options", sha).Output()

Commit 5f3b0a7e1a

Commit `5f3b0a7e1a`