Merge pull request #1050 from onee-only/fix-empty-commit

git: worktree_commit, Modify checking empty commit. Fixes #723

4 files changed, 159 insertions, 24 deletions

diff --git a/repository_test.go b/repository_test.go
index b211f8c..0b77c5a 100644
--- a/repository_test.go
+++ b/repository_test.go
@@ -103,9 +103,10 @@ func createCommit(c *C, r *Repository) plumbing.Hash {
 	}
 
 	h, err := wt.Commit("test commit message", &CommitOptions{
-		All:       true,
-		Author:    &author,
-		Committer: &author,
+		All:               true,
+		Author:            &author,
+		Committer:         &author,
+		AllowEmptyCommits: true,
 	})
 	c.Assert(err, IsNil)
 	return h
diff --git a/worktree_commit.go b/worktree_commit.go
index f62054b..2faf6f0 100644
--- a/worktree_commit.go
+++ b/worktree_commit.go
@@ -38,8 +38,6 @@ func (w *Worktree) Commit(msg string, opts *CommitOptions) (plumbing.Hash, error
 		}
 	}
 
-	var treeHash plumbing.Hash
-
 	if opts.Amend {
 		head, err := w.r.Head()
 		if err != nil {
@@ -61,16 +59,34 @@ func (w *Worktree) Commit(msg string, opts *CommitOptions) (plumbing.Hash, error
 		return plumbing.ZeroHash, err
 	}
 
+	// First handle the case of the first commit in the repository being empty.
+	if len(opts.Parents) == 0 && len(idx.Entries) == 0 && !opts.AllowEmptyCommits {
+		return plumbing.ZeroHash, ErrEmptyCommit
+	}
+
 	h := &buildTreeHelper{
 		fs: w.Filesystem,
 		s:  w.r.Storer,
 	}
 
-	treeHash, err = h.BuildTree(idx, opts)
+	treeHash, err := h.BuildTree(idx, opts)
 	if err != nil {
 		return plumbing.ZeroHash, err
 	}
 
+	previousTree := plumbing.ZeroHash
+	if len(opts.Parents) > 0 {
+		parentCommit, err := w.r.CommitObject(opts.Parents[0])
+		if err != nil {
+			return plumbing.ZeroHash, err
+		}
+		previousTree = parentCommit.TreeHash
+	}
+
+	if treeHash == previousTree && !opts.AllowEmptyCommits {
+		return plumbing.ZeroHash, ErrEmptyCommit
+	}
+
 	commit, err := w.buildCommitObject(msg, opts, treeHash)
 	if err != nil {
 		return plumbing.ZeroHash, err
@@ -175,10 +191,6 @@ type buildTreeHelper struct {
 // BuildTree builds the tree objects and push its to the storer, the hash
 // of the root tree is returned.
 func (h *buildTreeHelper) BuildTree(idx *index.Index, opts *CommitOptions) (plumbing.Hash, error) {
-	if len(idx.Entries) == 0 && (opts == nil || !opts.AllowEmptyCommits) {
-		return plumbing.ZeroHash, ErrEmptyCommit
-	}
-
 	const rootNode = ""
 	h.trees = map[string]*object.Tree{rootNode: {}}
 	h.entries = map[string]*object.TreeEntry{}
diff --git a/worktree_commit_test.go b/worktree_commit_test.go
index ae8f841..e028fac 100644
--- a/worktree_commit_test.go
+++ b/worktree_commit_test.go
@@ -89,6 +89,56 @@ func (s *WorktreeSuite) TestNothingToCommit(c *C) {
 	c.Assert(err, IsNil)
 }
 
+func (s *WorktreeSuite) TestNothingToCommitNonEmptyRepo(c *C) {
+	fs := memfs.New()
+	r, err := Init(memory.NewStorage(), fs)
+	c.Assert(err, IsNil)
+
+	w, err := r.Worktree()
+	c.Assert(err, IsNil)
+
+	err = util.WriteFile(fs, "foo", []byte("foo"), 0644)
+	c.Assert(err, IsNil)
+
+	w.Add("foo")
+	_, err = w.Commit("previous commit\n", &CommitOptions{Author: defaultSignature()})
+	c.Assert(err, IsNil)
+
+	hash, err := w.Commit("failed empty commit\n", &CommitOptions{Author: defaultSignature()})
+	c.Assert(hash, Equals, plumbing.ZeroHash)
+	c.Assert(err, Equals, ErrEmptyCommit)
+
+	_, err = w.Commit("enable empty commits\n", &CommitOptions{Author: defaultSignature(), AllowEmptyCommits: true})
+	c.Assert(err, IsNil)
+}
+
+func (s *WorktreeSuite) TestRemoveAndCommitToMakeEmptyRepo(c *C) {
+	fs := memfs.New()
+	r, err := Init(memory.NewStorage(), fs)
+	c.Assert(err, IsNil)
+
+	w, err := r.Worktree()
+	c.Assert(err, IsNil)
+
+	err = util.WriteFile(fs, "foo", []byte("foo"), 0644)
+	c.Assert(err, IsNil)
+
+	_, err = w.Add("foo")
+	c.Assert(err, IsNil)
+
+	_, err = w.Commit("Add in Repo\n", &CommitOptions{Author: defaultSignature()})
+	c.Assert(err, IsNil)
+
+	err = fs.Remove("foo")
+	c.Assert(err, IsNil)
+
+	_, err = w.Add("foo")
+	c.Assert(err, IsNil)
+
+	_, err = w.Commit("Remove foo\n", &CommitOptions{Author: defaultSignature()})
+	c.Assert(err, IsNil)
+}
+
 func (s *WorktreeSuite) TestCommitParent(c *C) {
 	expected := plumbing.NewHash("ef3ca05477530b37f48564be33ddd48063fc7a22")
 
@@ -101,7 +151,8 @@ func (s *WorktreeSuite) TestCommitParent(c *C) {
 	err := w.Checkout(&CheckoutOptions{})
 	c.Assert(err, IsNil)
 
-	util.WriteFile(fs, "foo", []byte("foo"), 0644)
+	err = util.WriteFile(fs, "foo", []byte("foo"), 0644)
+	c.Assert(err, IsNil)
 
 	_, err = w.Add("foo")
 	c.Assert(err, IsNil)
@@ -113,7 +164,42 @@ func (s *WorktreeSuite) TestCommitParent(c *C) {
 	assertStorageStatus(c, s.Repository, 13, 11, 10, expected)
 }
 
-func (s *WorktreeSuite) TestCommitAmend(c *C) {
+func (s *WorktreeSuite) TestCommitAmendWithoutChanges(c *C) {
+	fs := memfs.New()
+	w := &Worktree{
+		r:          s.Repository,
+		Filesystem: fs,
+	}
+
+	err := w.Checkout(&CheckoutOptions{})
+	c.Assert(err, IsNil)
+
+	err = util.WriteFile(fs, "foo", []byte("foo"), 0644)
+	c.Assert(err, IsNil)
+
+	_, err = w.Add("foo")
+	c.Assert(err, IsNil)
+
+	prevHash, err := w.Commit("foo\n", &CommitOptions{Author: defaultSignature()})
+	c.Assert(err, IsNil)
+
+	amendedHash, err := w.Commit("foo\n", &CommitOptions{Author: defaultSignature(), Amend: true})
+	c.Assert(err, IsNil)
+
+	headRef, err := w.r.Head()
+	c.Assert(err, IsNil)
+
+	c.Assert(amendedHash, Equals, headRef.Hash())
+	c.Assert(amendedHash, Equals, prevHash)
+
+	commit, err := w.r.CommitObject(headRef.Hash())
+	c.Assert(err, IsNil)
+	c.Assert(commit.Message, Equals, "foo\n")
+
+	assertStorageStatus(c, s.Repository, 13, 11, 10, amendedHash)
+}
+
+func (s *WorktreeSuite) TestCommitAmendWithChanges(c *C) {
 	fs := memfs.New()
 	w := &Worktree{
 		r:          s.Repository,
@@ -164,6 +250,34 @@ func (s *WorktreeSuite) TestCommitAmend(c *C) {
 	assertStorageStatus(c, s.Repository, 14, 12, 11, amendedHash)
 }
 
+func (s *WorktreeSuite) TestCommitAmendNothingToCommit(c *C) {
+	fs := memfs.New()
+	w := &Worktree{
+		r:          s.Repository,
+		Filesystem: fs,
+	}
+
+	err := w.Checkout(&CheckoutOptions{})
+	c.Assert(err, IsNil)
+
+	err = util.WriteFile(fs, "foo", []byte("foo"), 0644)
+	c.Assert(err, IsNil)
+
+	_, err = w.Add("foo")
+	c.Assert(err, IsNil)
+
+	prevHash, err := w.Commit("foo\n", &CommitOptions{Author: defaultSignature()})
+	c.Assert(err, IsNil)
+
+	_, err = w.Commit("bar\n", &CommitOptions{Author: defaultSignature(), AllowEmptyCommits: true})
+	c.Assert(err, IsNil)
+
+	amendedHash, err := w.Commit("foo\n", &CommitOptions{Author: defaultSignature(), Amend: true})
+	c.Log(prevHash, amendedHash)
+	c.Assert(err, Equals, ErrEmptyCommit)
+	c.Assert(amendedHash, Equals, plumbing.ZeroHash)
+}
+
 func (s *WorktreeSuite) TestAddAndCommitWithSkipStatus(c *C) {
 	expected := plumbing.NewHash("375a3808ffde7f129cdd3c8c252fd0fe37cfd13b")
 
@@ -258,7 +372,8 @@ func (s *WorktreeSuite) TestAddAndCommitWithSkipStatusPathNotModified(c *C) {
 	c.Assert(foo.Worktree, Equals, Untracked)
 
 	hash, err = w.Commit("commit with no changes\n", &CommitOptions{
-		Author: defaultSignature(),
+		Author:            defaultSignature(),
+		AllowEmptyCommits: true,
 	})
 	c.Assert(hash, Equals, expected2)
 	c.Assert(err, IsNil)
diff --git a/worktree_test.go b/worktree_test.go
index f67cca2..3e151f6 100644
--- a/worktree_test.go
+++ b/worktree_test.go
@@ -32,9 +32,11 @@ import (
 	. "gopkg.in/check.v1"
 )
 
-var (
-	defaultTestCommitOptions = &CommitOptions{Author: &object.Signature{Name: "testuser", Email: "testemail"}}
-)
+func defaultTestCommitOptions() *CommitOptions {
+	return &CommitOptions{
+		Author: &object.Signature{Name: "testuser", Email: "testemail"},
+	}
+}
 
 type WorktreeSuite struct {
 	BaseSuite
@@ -87,8 +89,9 @@ func (s *WorktreeSuite) TestPullFastForward(c *C) {
 
 	w, err := server.Worktree()
 	c.Assert(err, IsNil)
-	err = os.WriteFile(filepath.Join(path, "foo"), []byte("foo"), 0755)
+	err = os.WriteFile(filepath.Join(url, "foo"), []byte("foo"), 0755)
 	c.Assert(err, IsNil)
+	w.Add("foo")
 	hash, err := w.Commit("foo", &CommitOptions{Author: defaultSignature()})
 	c.Assert(err, IsNil)
 
@@ -124,15 +127,17 @@ func (s *WorktreeSuite) TestPullNonFastForward(c *C) {
 
 	w, err := server.Worktree()
 	c.Assert(err, IsNil)
-	err = os.WriteFile(filepath.Join(path, "foo"), []byte("foo"), 0755)
+	err = os.WriteFile(filepath.Join(url, "foo"), []byte("foo"), 0755)
 	c.Assert(err, IsNil)
+	w.Add("foo")
 	_, err = w.Commit("foo", &CommitOptions{Author: defaultSignature()})
 	c.Assert(err, IsNil)
 
 	w, err = r.Worktree()
 	c.Assert(err, IsNil)
-	err = os.WriteFile(filepath.Join(path, "bar"), []byte("bar"), 0755)
+	err = os.WriteFile(filepath.Join(dir, "bar"), []byte("bar"), 0755)
 	c.Assert(err, IsNil)
+	w.Add("bar")
 	_, err = w.Commit("bar", &CommitOptions{Author: defaultSignature()})
 	c.Assert(err, IsNil)
 
@@ -285,7 +290,8 @@ func (s *RepositorySuite) TestPullAdd(c *C) {
 func (s *WorktreeSuite) TestPullAlreadyUptodate(c *C) {
 	path := fixtures.Basic().ByTag("worktree").One().Worktree().Root()
 
-	r, err := Clone(memory.NewStorage(), memfs.New(), &CloneOptions{
+	fs := memfs.New()
+	r, err := Clone(memory.NewStorage(), fs, &CloneOptions{
 		URL: filepath.Join(path, ".git"),
 	})
 
@@ -293,8 +299,9 @@ func (s *WorktreeSuite) TestPullAlreadyUptodate(c *C) {
 
 	w, err := r.Worktree()
 	c.Assert(err, IsNil)
-	err = os.WriteFile(filepath.Join(path, "bar"), []byte("bar"), 0755)
+	err = util.WriteFile(fs, "bar", []byte("bar"), 0755)
 	c.Assert(err, IsNil)
+	w.Add("bar")
 	_, err = w.Commit("bar", &CommitOptions{Author: defaultSignature()})
 	c.Assert(err, IsNil)
 
@@ -1001,14 +1008,14 @@ func (s *WorktreeSuite) TestStatusCheckedInBeforeIgnored(c *C) {
 	_, err = w.Add("fileToIgnore")
 	c.Assert(err, IsNil)
 
-	_, err = w.Commit("Added file that will be ignored later", defaultTestCommitOptions)
+	_, err = w.Commit("Added file that will be ignored later", defaultTestCommitOptions())
 	c.Assert(err, IsNil)
 
 	err = util.WriteFile(fs, ".gitignore", []byte("fileToIgnore\nsecondIgnoredFile"), 0755)
 	c.Assert(err, IsNil)
 	_, err = w.Add(".gitignore")
 	c.Assert(err, IsNil)
-	_, err = w.Commit("Added .gitignore", defaultTestCommitOptions)
+	_, err = w.Commit("Added .gitignore", defaultTestCommitOptions())
 	c.Assert(err, IsNil)
 	status, err := w.Status()
 	c.Assert(err, IsNil)
@@ -2056,7 +2063,7 @@ func (s *WorktreeSuite) TestAddSkipStatusWithIgnoredPath(c *C) {
 	c.Assert(err, IsNil)
 	_, err = w.Add(".gitignore")
 	c.Assert(err, IsNil)
-	_, err = w.Commit("Added .gitignore", defaultTestCommitOptions)
+	_, err = w.Commit("Added .gitignore", defaultTestCommitOptions())
 	c.Assert(err, IsNil)
 
 	err = util.WriteFile(fs, "fileToIgnore", []byte("file to ignore"), 0644)