repository: fix plain clone error handling regression

PR #1008 introduced a regression by changing the errors returned by
PlainClone when a repository did not exist.

This change goes back to returned errors as they were in v4.7.0.

Fixes #1027

Signed-off-by: Santiago M. Mola <santi@mola.io>

2 files changed, 57 insertions, 19 deletions

diff --git a/repository.go b/repository.go
index f548e9a..97134ec 100644
--- a/repository.go
+++ b/repository.go
@@ -342,8 +342,9 @@ func PlainClone(path string, isBare bool, o *CloneOptions) (*Repository, error)
 // transport operations.
 //
 // TODO(mcuadros): move isBare to CloneOptions in v5
+// TODO(smola): refuse upfront to clone on a non-empty directory in v5, see #1027
 func PlainCloneContext(ctx context.Context, path string, isBare bool, o *CloneOptions) (*Repository, error) {
-	dirExists, err := checkExistsAndIsEmptyDir(path)
+	cleanup, cleanupParent, err := checkIfCleanupIsNeeded(path)
 	if err != nil {
 		return nil, err
 	}
@@ -355,7 +356,9 @@ func PlainCloneContext(ctx context.Context, path string, isBare bool, o *CloneOp
 
 	err = r.clone(ctx, o)
 	if err != nil && err != ErrRepositoryAlreadyExists {
-		cleanUpDir(path, !dirExists)
+		if cleanup {
+			cleanUpDir(path, cleanupParent)
+		}
 	}
 
 	return r, err
@@ -369,37 +372,37 @@ func newRepository(s storage.Storer, worktree billy.Filesystem) *Repository {
 	}
 }
 
-func checkExistsAndIsEmptyDir(path string) (exists bool, err error) {
+func checkIfCleanupIsNeeded(path string) (cleanup bool, cleanParent bool, err error) {
 	fi, err := os.Stat(path)
 	if err != nil {
 		if os.IsNotExist(err) {
-			return false, nil
+			return true, true, nil
 		}
 
-		return false, err
+		return false, false, err
 	}
 
 	if !fi.IsDir() {
-		return false, fmt.Errorf("path is not a directory: %s", path)
+		return false, false, fmt.Errorf("path is not a directory: %s", path)
 	}
 
 	f, err := os.Open(path)
 	if err != nil {
-		return false, err
+		return false, false, err
 	}
 
 	defer ioutil.CheckClose(f, &err)
 
 	_, err = f.Readdirnames(1)
 	if err == io.EOF {
-		return true, nil
+		return true, false, nil
 	}
 
 	if err != nil {
-		return true, err
+		return false, false, err
 	}
 
-	return true, fmt.Errorf("directory is not empty: %s", path)
+	return false, false, nil
 }
 
 func cleanUpDir(path string, all bool) error {
@@ -425,7 +428,7 @@ func cleanUpDir(path string, all bool) error {
 		}
 	}
 
-	return nil
+	return err
 }
 
 // Config return the repository config
diff --git a/repository_test.go b/repository_test.go
index 59ab89e..70e344e 100644
--- a/repository_test.go
+++ b/repository_test.go
@@ -21,6 +21,7 @@ import (
 	"gopkg.in/src-d/go-git.v4/plumbing/cache"
 	"gopkg.in/src-d/go-git.v4/plumbing/object"
 	"gopkg.in/src-d/go-git.v4/plumbing/storer"
+	"gopkg.in/src-d/go-git.v4/plumbing/transport"
 	"gopkg.in/src-d/go-git.v4/storage"
 	"gopkg.in/src-d/go-git.v4/storage/filesystem"
 	"gopkg.in/src-d/go-git.v4/storage/memory"
@@ -177,11 +178,12 @@ func (s *RepositorySuite) TestCloneContext(c *C) {
 	ctx, cancel := context.WithCancel(context.Background())
 	cancel()
 
-	_, err := CloneContext(ctx, memory.NewStorage(), nil, &CloneOptions{
+	r, err := CloneContext(ctx, memory.NewStorage(), nil, &CloneOptions{
 		URL: s.GetBasicLocalRepositoryURL(),
 	})
 
-	c.Assert(err, NotNil)
+	c.Assert(r, NotNil)
+	c.Assert(err, ErrorMatches, ".* context canceled")
 }
 
 func (s *RepositorySuite) TestCloneWithTags(c *C) {
@@ -581,7 +583,20 @@ func (s *RepositorySuite) TestPlainCloneWithRemoteName(c *C) {
 	c.Assert(remote, NotNil)
 }
 
-func (s *RepositorySuite) TestPlainCloneContextWithProperParameters(c *C) {
+func (s *RepositorySuite) TestPlainCloneOverExistingGitDirectory(c *C) {
+	tmpDir := c.MkDir()
+	r, err := PlainInit(tmpDir, false)
+	c.Assert(r, NotNil)
+	c.Assert(err, IsNil)
+
+	r, err = PlainClone(tmpDir, false, &CloneOptions{
+		URL: s.GetBasicLocalRepositoryURL(),
+	})
+	c.Assert(r, IsNil)
+	c.Assert(err, Equals, ErrRepositoryAlreadyExists)
+}
+
+func (s *RepositorySuite) TestPlainCloneContextCancel(c *C) {
 	ctx, cancel := context.WithCancel(context.Background())
 	cancel()
 
@@ -590,7 +605,7 @@ func (s *RepositorySuite) TestPlainCloneContextWithProperParameters(c *C) {
 	})
 
 	c.Assert(r, NotNil)
-	c.Assert(err, NotNil)
+	c.Assert(err, ErrorMatches, ".* context canceled")
 }
 
 func (s *RepositorySuite) TestPlainCloneContextNonExistentWithExistentDir(c *C) {
@@ -604,7 +619,7 @@ func (s *RepositorySuite) TestPlainCloneContextNonExistentWithExistentDir(c *C)
 		URL: "incorrectOnPurpose",
 	})
 	c.Assert(r, NotNil)
-	c.Assert(err, NotNil)
+	c.Assert(err, Equals, transport.ErrRepositoryNotFound)
 
 	_, err = os.Stat(repoDir)
 	c.Assert(os.IsNotExist(err), Equals, false)
@@ -625,7 +640,7 @@ func (s *RepositorySuite) TestPlainCloneContextNonExistentWithNonExistentDir(c *
 		URL: "incorrectOnPurpose",
 	})
 	c.Assert(r, NotNil)
-	c.Assert(err, NotNil)
+	c.Assert(err, Equals, transport.ErrRepositoryNotFound)
 
 	_, err = os.Stat(repoDir)
 	c.Assert(os.IsNotExist(err), Equals, true)
@@ -645,7 +660,7 @@ func (s *RepositorySuite) TestPlainCloneContextNonExistentWithNotDir(c *C) {
 		URL: "incorrectOnPurpose",
 	})
 	c.Assert(r, IsNil)
-	c.Assert(err, NotNil)
+	c.Assert(err, ErrorMatches, ".*not a directory.*")
 
 	fi, err := os.Stat(repoDir)
 	c.Assert(err, IsNil)
@@ -668,8 +683,28 @@ func (s *RepositorySuite) TestPlainCloneContextNonExistentWithNotEmptyDir(c *C)
 	r, err := PlainCloneContext(ctx, repoDirPath, false, &CloneOptions{
 		URL: "incorrectOnPurpose",
 	})
+	c.Assert(r, NotNil)
+	c.Assert(err, Equals, transport.ErrRepositoryNotFound)
+
+	_, err = os.Stat(dummyFile)
+	c.Assert(err, IsNil)
+
+}
+
+func (s *RepositorySuite) TestPlainCloneContextNonExistingOverExistingGitDirectory(c *C) {
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel()
+
+	tmpDir := c.MkDir()
+	r, err := PlainInit(tmpDir, false)
+	c.Assert(r, NotNil)
+	c.Assert(err, IsNil)
+
+	r, err = PlainCloneContext(ctx, tmpDir, false, &CloneOptions{
+		URL: "incorrectOnPurpose",
+	})
 	c.Assert(r, IsNil)
-	c.Assert(err, NotNil)
+	c.Assert(err, Equals, ErrRepositoryAlreadyExists)
 }
 
 func (s *RepositorySuite) TestPlainCloneWithRecurseSubmodules(c *C) {