Repository: Clone protection if non empty object storage, Remote: NoErrAlreadyUpToDate

8 files changed, 100 insertions, 16 deletions

diff --git a/commit_test.go b/commit_test.go
index 9a05cd8..626fdcf 100644
--- a/commit_test.go
+++ b/commit_test.go
@@ -15,8 +15,8 @@ type SuiteCommit struct {
 
 var _ = Suite(&SuiteCommit{})
 
-func (s *SuiteCommit) SetUpTest(c *C) {
-	s.BaseSuite.SetUpTest(c)
+func (s *SuiteCommit) SetUpSuite(c *C) {
+	s.BaseSuite.SetUpSuite(c)
 
 	hash := core.NewHash("1669dce138d9b841a518c64b10914d88f5e488ea")
 
diff --git a/common_test.go b/common_test.go
index dbacddd..e02e9d6 100644
--- a/common_test.go
+++ b/common_test.go
@@ -22,7 +22,7 @@ type BaseSuite struct {
 	Repository *Repository
 }
 
-func (s *BaseSuite) SetUpTest(c *C) {
+func (s *BaseSuite) SetUpSuite(c *C) {
 	clients.InstallProtocol("mock", func(end common.Endpoint) common.GitUploadPackService {
 		return &MockGitUploadPackService{endpoint: end}
 	})
@@ -75,12 +75,16 @@ func (p *MockGitUploadPackService) Info() (*common.GitUploadPackInfo, error) {
 	}, nil
 }
 
-func (p *MockGitUploadPackService) Fetch(*common.GitUploadPackRequest) (io.ReadCloser, error) {
+func (p *MockGitUploadPackService) Fetch(r *common.GitUploadPackRequest) (io.ReadCloser, error) {
 	if !p.connected {
 		return nil, errors.New("not connected")
 	}
 
-	return os.Open("formats/packfile/fixtures/git-fixture.ref-delta")
+	if len(r.Wants) == 1 {
+		return os.Open("formats/packfile/fixtures/git-fixture.ref-delta")
+	}
+
+	return os.Open("fixtures/pack-63bbc2e1bde392e2205b30fa3584ddb14ef8bd41.pack")
 }
 
 func (p *MockGitUploadPackService) Disconnect() error {
diff --git a/file_test.go b/file_test.go
index e49970a..e545d99 100644
--- a/file_test.go
+++ b/file_test.go
@@ -17,6 +17,8 @@ var _ = Suite(&SuiteFile{})
 
 // create the repositories of the fixtures
 func (s *SuiteFile) SetUpSuite(c *C) {
+	s.BaseSuite.SetUpSuite(c)
+
 	fileFixtures := []packedFixture{
 		{"https://github.com/tyba/git-fixture.git", "formats/packfile/fixtures/git-fixture.ofs-delta"},
 		{"https://github.com/cpcs499/Final_Pres_P", "formats/packfile/fixtures/Final_Pres_P.ofs-delta"},
diff --git a/objects_test.go b/objects_test.go
index b36bb85..df62fe1 100644
--- a/objects_test.go
+++ b/objects_test.go
@@ -16,8 +16,8 @@ type ObjectsSuite struct {
 
 var _ = Suite(&ObjectsSuite{})
 
-func (s *ObjectsSuite) SetUpTest(c *C) {
-	s.BaseSuite.SetUpTest(c)
+func (s *ObjectsSuite) SetUpSuite(c *C) {
+	s.BaseSuite.SetUpSuite(c)
 
 	s.r = NewMemoryRepository()
 	err := s.r.Clone(&CloneOptions{URL: RepositoryFixture})
diff --git a/remote.go b/remote.go
index a8b77b1..f918f3d 100644
--- a/remote.go
+++ b/remote.go
@@ -1,6 +1,7 @@
 package git
 
 import (
+	"errors"
 	"fmt"
 	"io"
 
@@ -11,6 +12,8 @@ import (
 	"gopkg.in/src-d/go-git.v4/formats/packfile"
 )
 
+var NoErrAlreadyUpToDate = errors.New("already up-to-date")
+
 // Remote represents a connection to a remote repository
 type Remote struct {
 	c *config.RemoteConfig
@@ -87,6 +90,10 @@ func (r *Remote) Fetch(o *FetchOptions) (err error) {
 		return err
 	}
 
+	if len(refs) == 0 {
+		return NoErrAlreadyUpToDate
+	}
+
 	req, err := r.buildRequest(r.s.ReferenceStorage(), o, refs)
 	if err != nil {
 		return err
@@ -107,17 +114,22 @@ func (r *Remote) Fetch(o *FetchOptions) (err error) {
 
 func (r *Remote) getWantedReferences(spec []config.RefSpec) ([]*core.Reference, error) {
 	var refs []*core.Reference
+	return refs, r.Refs().ForEach(func(ref *core.Reference) error {
+		if ref.Type() != core.HashReference {
+			return nil
+		}
 
-	return refs, r.Refs().ForEach(func(r *core.Reference) error {
-		if r.Type() != core.HashReference {
+		if !config.MatchAny(spec, ref.Name()) {
 			return nil
 		}
 
-		if config.MatchAny(spec, r.Name()) {
-			refs = append(refs, r)
+		_, err := r.s.ObjectStorage().Get(ref.Hash())
+		if err == core.ErrObjectNotFound {
+			refs = append(refs, ref)
+			return nil
 		}
 
-		return nil
+		return err
 	})
 }
 
diff --git a/remote_test.go b/remote_test.go
index 00766ad..9bafcd1 100644
--- a/remote_test.go
+++ b/remote_test.go
@@ -83,7 +83,24 @@ func (s *RemoteSuite) TestFetch(c *C) {
 	})
 
 	c.Assert(err, IsNil)
-	c.Assert(sto.ObjectStorage().(*memory.ObjectStorage).Objects, HasLen, 28)
+	c.Assert(sto.ObjectStorage().(*memory.ObjectStorage).Objects, HasLen, 31)
+}
+
+func (s *RemoteSuite) TestFetchNoErrAlreadyUpToDate(c *C) {
+	sto := memory.NewStorage()
+	r := newRemote(sto, &config.RemoteConfig{Name: "foo", URL: RepositoryFixture})
+	r.upSrv = &MockGitUploadPackService{}
+
+	c.Assert(r.Connect(), IsNil)
+
+	o := &FetchOptions{
+		RefSpecs: []config.RefSpec{config.DefaultRefSpec},
+	}
+
+	err := r.Fetch(o)
+	c.Assert(err, IsNil)
+	err = r.Fetch(o)
+	c.Assert(err, Equals, NoErrAlreadyUpToDate)
 }
 
 func (s *RemoteSuite) TestHead(c *C) {
diff --git a/repository.go b/repository.go
index 445e90c..fc871c7 100644
--- a/repository.go
+++ b/repository.go
@@ -12,8 +12,9 @@ import (
 )
 
 var (
-	ErrObjectNotFound   = errors.New("object not found")
-	ErrInvalidReference = errors.New("invalid reference, should be a tag or a branch")
+	ErrObjectNotFound     = errors.New("object not found")
+	ErrInvalidReference   = errors.New("invalid reference, should be a tag or a branch")
+	ErrRepositoryNonEmpty = errors.New("repository non empty")
 )
 
 // Repository giturl string, auth common.AuthMethod repository struct
@@ -94,6 +95,15 @@ func (r *Repository) DeleteRemote(name string) error {
 
 // Clone clones a remote repository
 func (r *Repository) Clone(o *CloneOptions) error {
+	empty, err := r.IsEmpty()
+	if err != nil {
+		return err
+	}
+
+	if !empty {
+		return ErrRepositoryNonEmpty
+	}
+
 	if err := o.Validate(); err != nil {
 		return err
 	}
@@ -166,6 +176,15 @@ func (r *Repository) createReferences(ref *core.Reference) error {
 	return r.s.ReferenceStorage().Set(head)
 }
 
+// IsEmpty returns true if the repository is empty
+func (r *Repository) IsEmpty() (bool, error) {
+	var count int
+	return count == 0, r.Refs().ForEach(func(r *core.Reference) error {
+		count++
+		return nil
+	})
+}
+
 // Pull incorporates changes from a remote repository into the current branch
 func (r *Repository) Pull(o *PullOptions) error {
 	if err := o.Validate(); err != nil {
diff --git a/repository_test.go b/repository_test.go
index ce53ead..bfb0298 100644
--- a/repository_test.go
+++ b/repository_test.go
@@ -106,6 +106,21 @@ func (s *RepositorySuite) TestClone(c *C) {
 	c.Assert(branch.Hash().String(), Equals, "e8d3ffab552895c19b9fcf7aa264d277cde33881")
 }
 
+func (s *RepositorySuite) TestCloneNonEmpty(c *C) {
+	r := NewMemoryRepository()
+
+	head, err := r.Head()
+	c.Assert(err, Equals, core.ErrReferenceNotFound)
+	c.Assert(head, IsNil)
+
+	o := &CloneOptions{URL: RepositoryFixture}
+	err = r.Clone(o)
+	c.Assert(err, IsNil)
+
+	err = r.Clone(o)
+	c.Assert(err, Equals, ErrRepositoryNonEmpty)
+}
+
 func (s *RepositorySuite) TestCloneSingleBranchAndNonHEAD(c *C) {
 	r := NewMemoryRepository()
 
@@ -193,6 +208,21 @@ func (s *RepositorySuite) TestCloneDetachedHEAD(c *C) {
 	c.Assert(head.Hash().String(), Equals, "6ecf0ef2c2dffb796033e5a02219af86ec6584e5")
 }
 
+func (s *RepositorySuite) TestIsEmpty(c *C) {
+	r := NewMemoryRepository()
+
+	empty, err := r.IsEmpty()
+	c.Assert(err, IsNil)
+	c.Assert(empty, Equals, true)
+
+	err = r.Clone(&CloneOptions{URL: RepositoryFixture})
+	c.Assert(err, IsNil)
+
+	empty, err = r.IsEmpty()
+	c.Assert(err, IsNil)
+	c.Assert(empty, Equals, false)
+}
+
 func (s *RepositorySuite) TestCommit(c *C) {
 	r := NewMemoryRepository()
 	err := r.Clone(&CloneOptions{
@@ -237,7 +267,7 @@ func (s *RepositorySuite) TestCommits(c *C) {
 		c.Assert(commit.Type(), Equals, core.CommitObject)
 	}
 
-	c.Assert(count, Equals, 8)
+	c.Assert(count, Equals, 9)
 }
 
 func (s *RepositorySuite) TestTag(c *C) {