storage/filesystem: call initialization explicitely, fixes #408

filesystem.Storage was initializing the gitdir (creating objects
and refs) on NewStorage. But this should be done only on init and
clone operations, not on open.

Now there is a new interface storer.Initializer that storers can
implement if they need any initialization step before init or clone.
filesystem.Storage is one of such implementations.

git.Init and git.Clone now call to the storer Init() method if it
does implement it. Otherwise, it just ignores initialization.

1 files changed, 13 insertions, 0 deletions

diff --git a/repository.go b/repository.go
index 76be660..35aae52 100644
--- a/repository.go
+++ b/repository.go
@@ -44,6 +44,10 @@ type Repository struct {
 // The worktree Filesystem is optional, if nil a bare repository is created. If
 // the given storer is not empty ErrRepositoryAlreadyExists is returned
 func Init(s storage.Storer, worktree billy.Filesystem) (*Repository, error) {
+	if err := initStorer(s); err != nil {
+		return nil, err
+	}
+
 	r := newRepository(s, worktree)
 	_, err := r.Reference(plumbing.HEAD, false)
 	switch err {
@@ -67,6 +71,15 @@ func Init(s storage.Storer, worktree billy.Filesystem) (*Repository, error) {
 	return r, setWorktreeAndStoragePaths(r, worktree)
 }
 
+func initStorer(s storer.Storer) error {
+	i, ok := s.(storer.Initializer)
+	if !ok {
+		return nil
+	}
+
+	return i.Init()
+}
+
 func setWorktreeAndStoragePaths(r *Repository, worktree billy.Filesystem) error {
 	type fsBased interface {
 		Filesystem() billy.Filesystem