Merge branch 'master' into jc/commit-ammend

1 files changed, 16 insertions, 5 deletions

diff --git a/worktree_commit.go b/worktree_commit.go
index 86320d8..eaa21c3 100644
--- a/worktree_commit.go
+++ b/worktree_commit.go
@@ -2,6 +2,7 @@ package git
 
 import (
 	"bytes"
+	"errors"
 	"path"
 	"sort"
 	"strings"
@@ -16,6 +17,12 @@ import (
 	"github.com/go-git/go-billy/v5"
 )
 
+var (
+	// ErrEmptyCommit occurs when a commit is attempted using a clean
+	// working tree, with no changes to be committed.
+	ErrEmptyCommit = errors.New("cannot create empty commit: clean working tree")
+)
+
 // Commit stores the current contents of the index in a new commit along with
 // a log message from the user describing the changes.
 func (w *Worktree) Commit(msg string, opts *CommitOptions) (plumbing.Hash, error) {
@@ -37,14 +44,14 @@ func (w *Worktree) Commit(msg string, opts *CommitOptions) (plumbing.Hash, error
 			return plumbing.ZeroHash, err
 		}
 
-		t, err := w.getTreeFromCommitHash(head.Hash())
+		t, err := w.r.getTreeFromCommitHash(head.Hash())
 		if err != nil {
 			return plumbing.ZeroHash, err
 		}
 
 		treeHash = t.Hash
 		opts.Parents = []plumbing.Hash{head.Hash()}
-	}else {
+	} else {
 		idx, err := w.r.Storer.Index()
 		if err != nil {
 			return plumbing.ZeroHash, err
@@ -55,7 +62,7 @@ func (w *Worktree) Commit(msg string, opts *CommitOptions) (plumbing.Hash, error
 			s:  w.r.Storer,
 		}
 
-		treeHash, err = h.BuildTree(idx)
+		treeHash, err = h.BuildTree(idx, opts)
 		if err != nil {
 			return plumbing.ZeroHash, err
 		}
@@ -162,7 +169,11 @@ 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) (plumbing.Hash, error) {
+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{}
@@ -252,4 +263,4 @@ func (h *buildTreeHelper) copyTreeToStorageRecursive(parent string, t *object.Tr
 		return hash, nil
 	}
 	return h.s.SetEncodedObject(o)
-}
+}
\ No newline at end of file