git: worktree, Build status based on the current index instead of bui…

…lding it empty. Fixes go-git#119

worktree_status.go

@@ -47,8 +47,45 @@ func (w *Worktree) Status() (Status, error) {
 	return w.status(hash)
 }
 
+func (w *Worktree) newStatusFromIndex() (Status, error) {
+	idx, err := w.r.Storer.Index()
+	if err != nil {
+		return nil, err
+	}
+
+	idxRoot := mindex.NewRootNode(idx)
+	nodes := []noder.Noder{idxRoot}
+
+	if err != nil {
+		return nil, err
+	}
+
+	status := make(Status)
+
+	for len(nodes) > 0 {
+		var node noder.Noder
+		node, nodes = nodes[0], nodes[1:]
+		if node.IsDir() {
+			children, err := node.Children()
+			if err != nil {
+				return nil, err
+			}
+			nodes = append(nodes, children...)
+			continue
+		}
+		fs := status.File(node.Name())
+		fs.Worktree = Unmodified
+		fs.Staging = Unmodified
+	}
+
+	return status, nil
+}
+
 func (w *Worktree) status(commit plumbing.Hash) (Status, error) {
-	s := make(Status)
+	s, err := w.newStatusFromIndex()
+	if err != nil {
+		return nil, err
+	}
 
 	left, err := w.diffCommitWithStaging(commit, false)
 	if err != nil {

worktree_test.go

@@ -1052,6 +1052,25 @@ func (s *WorktreeSuite) TestStatusEmptyDirty(c *C) {
 	c.Assert(status, HasLen, 1)
 }
 
+func (s *WorktreeSuite) TestStatusUnmodified(c *C) {
+	fs := memfs.New()
+	w := &Worktree{
+		r:          s.Repository,
+		Filesystem: fs,
+	}
+
+	err := w.Checkout(&CheckoutOptions{Force: true})
+	c.Assert(err, IsNil)
+
+	status, err := w.Status()
+	c.Assert(err, IsNil)
+	c.Assert(status.IsClean(), Equals, true)
+	c.Assert(status.IsUntracked("LICENSE"), Equals, false)
+
+	c.Assert(status.File("LICENSE").Staging, Equals, Unmodified)
+	c.Assert(status.File("LICENSE").Worktree, Equals, Unmodified)
+}
+
 func (s *WorktreeSuite) TestReset(c *C) {
 	fs := memfs.New()
 	w := &Worktree{