*: Use CheckClose with named returns

Previously some close errors were losts. This is specially problematic
in go-git as lots of work is done here like generating indexes and
moving packfiles.

Signed-off-by: Javi Fontan <jfontan@gmail.com>

15 files changed, 38 insertions, 39 deletions

diff --git a/plumbing/format/packfile/common.go b/plumbing/format/packfile/common.go
index 7dad1f6..beb015d 100644
--- a/plumbing/format/packfile/common.go
+++ b/plumbing/format/packfile/common.go
@@ -40,8 +40,7 @@ func UpdateObjectStorage(s storer.EncodedObjectStorer, packfile io.Reader) error
 	return err
 }
 
-func writePackfileToObjectStorage(sw storer.PackfileWriter, packfile io.Reader) error {
-	var err error
+func writePackfileToObjectStorage(sw storer.PackfileWriter, packfile io.Reader) (err error) {
 	w, err := sw.PackfileWriter()
 	if err != nil {
 		return err
diff --git a/plumbing/format/packfile/scanner.go b/plumbing/format/packfile/scanner.go
index 8c216f1..6fc183b 100644
--- a/plumbing/format/packfile/scanner.go
+++ b/plumbing/format/packfile/scanner.go
@@ -279,14 +279,15 @@ func (s *Scanner) NextObject(w io.Writer) (written int64, crc32 uint32, err erro
 // from it zlib stream in an object entry in the packfile.
 func (s *Scanner) copyObject(w io.Writer) (n int64, err error) {
 	if s.zr == nil {
-		zr, err := zlib.NewReader(s.r)
+		var zr io.ReadCloser
+		zr, err = zlib.NewReader(s.r)
 		if err != nil {
 			return 0, fmt.Errorf("zlib initialization error: %s", err)
 		}
 
 		s.zr = zr.(readerResetter)
 	} else {
-		if err := s.zr.Reset(s.r, nil); err != nil {
+		if err = s.zr.Reset(s.r, nil); err != nil {
 			return 0, fmt.Errorf("zlib reset error: %s", err)
 		}
 	}
diff --git a/plumbing/object/blob.go b/plumbing/object/blob.go
index 2608477..f376baa 100644
--- a/plumbing/object/blob.go
+++ b/plumbing/object/blob.go
@@ -67,7 +67,7 @@ func (b *Blob) Decode(o plumbing.EncodedObject) error {
 }
 
 // Encode transforms a Blob into a plumbing.EncodedObject.
-func (b *Blob) Encode(o plumbing.EncodedObject) error {
+func (b *Blob) Encode(o plumbing.EncodedObject) (err error) {
 	o.SetType(plumbing.BlobObject)
 
 	w, err := o.Writer()
diff --git a/plumbing/object/commit.go b/plumbing/object/commit.go
index a317714..c9a4c0e 100644
--- a/plumbing/object/commit.go
+++ b/plumbing/object/commit.go
@@ -226,7 +226,7 @@ func (b *Commit) Encode(o plumbing.EncodedObject) error {
 	return b.encode(o, true)
 }
 
-func (b *Commit) encode(o plumbing.EncodedObject, includeSig bool) error {
+func (b *Commit) encode(o plumbing.EncodedObject, includeSig bool) (err error) {
 	o.SetType(plumbing.CommitObject)
 	w, err := o.Writer()
 	if err != nil {
diff --git a/plumbing/object/file.go b/plumbing/object/file.go
index 40b5206..1c5fdbb 100644
--- a/plumbing/object/file.go
+++ b/plumbing/object/file.go
@@ -44,7 +44,7 @@ func (f *File) Contents() (content string, err error) {
 }
 
 // IsBinary returns if the file is binary or not
-func (f *File) IsBinary() (bool, error) {
+func (f *File) IsBinary() (bin bool, err error) {
 	reader, err := f.Reader()
 	if err != nil {
 		return false, err
diff --git a/plumbing/object/tag.go b/plumbing/object/tag.go
index 19e55cf..905206b 100644
--- a/plumbing/object/tag.go
+++ b/plumbing/object/tag.go
@@ -95,7 +95,8 @@ func (t *Tag) Decode(o plumbing.EncodedObject) (err error) {
 
 	r := bufio.NewReader(reader)
 	for {
-		line, err := r.ReadBytes('\n')
+		var line []byte
+		line, err = r.ReadBytes('\n')
 		if err != nil && err != io.EOF {
 			return err
 		}
@@ -168,7 +169,7 @@ func (t *Tag) Encode(o plumbing.EncodedObject) error {
 	return t.encode(o, true)
 }
 
-func (t *Tag) encode(o plumbing.EncodedObject, includeSig bool) error {
+func (t *Tag) encode(o plumbing.EncodedObject, includeSig bool) (err error) {
 	o.SetType(plumbing.TagObject)
 	w, err := o.Writer()
 	if err != nil {
diff --git a/plumbing/object/tree.go b/plumbing/object/tree.go
index 2fcd979..c2399f8 100644
--- a/plumbing/object/tree.go
+++ b/plumbing/object/tree.go
@@ -233,7 +233,7 @@ func (t *Tree) Decode(o plumbing.EncodedObject) (err error) {
 }
 
 // Encode transforms a Tree into a plumbing.EncodedObject.
-func (t *Tree) Encode(o plumbing.EncodedObject) error {
+func (t *Tree) Encode(o plumbing.EncodedObject) (err error) {
 	o.SetType(plumbing.TreeObject)
 	w, err := o.Writer()
 	if err != nil {
@@ -242,7 +242,7 @@ func (t *Tree) Encode(o plumbing.EncodedObject) error {
 
 	defer ioutil.CheckClose(w, &err)
 	for _, entry := range t.Entries {
-		if _, err := fmt.Fprintf(w, "%o %s", entry.Mode, entry.Name); err != nil {
+		if _, err = fmt.Fprintf(w, "%o %s", entry.Mode, entry.Name); err != nil {
 			return err
 		}
 
diff --git a/plumbing/transport/http/common.go b/plumbing/transport/http/common.go
index 24e63a4..2c337b7 100644
--- a/plumbing/transport/http/common.go
+++ b/plumbing/transport/http/common.go
@@ -31,7 +31,7 @@ func applyHeadersToRequest(req *http.Request, content *bytes.Buffer, host string
 
 const infoRefsPath = "/info/refs"
 
-func advertisedReferences(s *session, serviceName string) (*packp.AdvRefs, error) {
+func advertisedReferences(s *session, serviceName string) (ref *packp.AdvRefs, err error) {
 	url := fmt.Sprintf(
 		"%s%s?service=%s",
 		s.endpoint.String(), infoRefsPath, serviceName,
@@ -52,12 +52,12 @@ func advertisedReferences(s *session, serviceName string) (*packp.AdvRefs, error
 	s.ModifyEndpointIfRedirect(res)
 	defer ioutil.CheckClose(res.Body, &err)
 
-	if err := NewErr(res); err != nil {
+	if err = NewErr(res); err != nil {
 		return nil, err
 	}
 
 	ar := packp.NewAdvRefs()
-	if err := ar.Decode(res.Body); err != nil {
+	if err = ar.Decode(res.Body); err != nil {
 		if err == packp.ErrEmptyAdvRefs {
 			err = transport.ErrEmptyRemoteRepository
 		}
diff --git a/remote.go b/remote.go
index 8db645c..666c9f5 100644
--- a/remote.go
+++ b/remote.go
@@ -73,7 +73,7 @@ func (r *Remote) Push(o *PushOptions) error {
 // The provided Context must be non-nil. If the context expires before the
 // operation is complete, an error is returned. The context only affects to the
 // transport operations.
-func (r *Remote) PushContext(ctx context.Context, o *PushOptions) error {
+func (r *Remote) PushContext(ctx context.Context, o *PushOptions) (err error) {
 	if err := o.Validate(); err != nil {
 		return err
 	}
@@ -243,12 +243,12 @@ func (r *Remote) Fetch(o *FetchOptions) error {
 	return r.FetchContext(context.Background(), o)
 }
 
-func (r *Remote) fetch(ctx context.Context, o *FetchOptions) (storer.ReferenceStorer, error) {
+func (r *Remote) fetch(ctx context.Context, o *FetchOptions) (sto storer.ReferenceStorer, err error) {
 	if o.RemoteName == "" {
 		o.RemoteName = r.c.Name
 	}
 
-	if err := o.Validate(); err != nil {
+	if err = o.Validate(); err != nil {
 		return nil, err
 	}
 
@@ -295,7 +295,7 @@ func (r *Remote) fetch(ctx context.Context, o *FetchOptions) (storer.ReferenceSt
 			return nil, err
 		}
 
-		if err := r.fetchPack(ctx, o, s, req); err != nil {
+		if err = r.fetchPack(ctx, o, s, req); err != nil {
 			return nil, err
 		}
 	}
@@ -354,7 +354,7 @@ func (r *Remote) fetchPack(ctx context.Context, o *FetchOptions, s transport.Upl
 
 	defer ioutil.CheckClose(reader, &err)
 
-	if err := r.updateShallow(o, reader); err != nil {
+	if err = r.updateShallow(o, reader); err != nil {
 		return err
 	}
 
@@ -872,7 +872,7 @@ func (r *Remote) buildFetchedTags(refs memory.ReferenceStorage) (updated bool, e
 }
 
 // List the references on the remote repository.
-func (r *Remote) List(o *ListOptions) ([]*plumbing.Reference, error) {
+func (r *Remote) List(o *ListOptions) (rfs []*plumbing.Reference, err error) {
 	s, err := newUploadPackSession(r.c.URLs[0], o.Auth)
 	if err != nil {
 		return nil, err
diff --git a/repository.go b/repository.go
index 98558d9..4ea51f5 100644
--- a/repository.go
+++ b/repository.go
@@ -270,9 +270,7 @@ func dotGitToOSFilesystems(path string) (dot, wt billy.Filesystem, err error) {
 	return dot, fs, nil
 }
 
-func dotGitFileToOSFilesystem(path string, fs billy.Filesystem) (billy.Filesystem, error) {
-	var err error
-
+func dotGitFileToOSFilesystem(path string, fs billy.Filesystem) (bfs billy.Filesystem, err error) {
 	f, err := fs.Open(".git")
 	if err != nil {
 		return nil, err
@@ -1092,7 +1090,7 @@ func (r *Repository) createNewObjectPack(cfg *RepackConfig) (h plumbing.Hash, er
 	if los, ok := r.Storer.(storer.LooseObjectStorer); ok {
 		err = los.ForEachObjectHash(func(hash plumbing.Hash) error {
 			if ow.isSeen(hash) {
-				err := los.DeleteLooseObject(hash)
+				err = los.DeleteLooseObject(hash)
 				if err != nil {
 					return err
 				}
diff --git a/storage/filesystem/config.go b/storage/filesystem/config.go
index a2cc173..85feaf0 100644
--- a/storage/filesystem/config.go
+++ b/storage/filesystem/config.go
@@ -13,7 +13,7 @@ type ConfigStorage struct {
 	dir *dotgit.DotGit
 }
 
-func (c *ConfigStorage) Config() (*config.Config, error) {
+func (c *ConfigStorage) Config() (conf *config.Config, err error) {
 	cfg := config.NewConfig()
 
 	f, err := c.dir.Config()
@@ -32,15 +32,15 @@ func (c *ConfigStorage) Config() (*config.Config, error) {
 		return nil, err
 	}
 
-	if err := cfg.Unmarshal(b); err != nil {
+	if err = cfg.Unmarshal(b); err != nil {
 		return nil, err
 	}
 
 	return cfg, err
 }
 
-func (c *ConfigStorage) SetConfig(cfg *config.Config) error {
-	if err := cfg.Validate(); err != nil {
+func (c *ConfigStorage) SetConfig(cfg *config.Config) (err error) {
+	if err = cfg.Validate(); err != nil {
 		return err
 	}
 
diff --git a/storage/filesystem/index.go b/storage/filesystem/index.go
index 14ab09a..092edec 100644
--- a/storage/filesystem/index.go
+++ b/storage/filesystem/index.go
@@ -12,7 +12,7 @@ type IndexStorage struct {
 	dir *dotgit.DotGit
 }
 
-func (s *IndexStorage) SetIndex(idx *index.Index) error {
+func (s *IndexStorage) SetIndex(idx *index.Index) (err error) {
 	f, err := s.dir.IndexWriter()
 	if err != nil {
 		return err
@@ -25,7 +25,7 @@ func (s *IndexStorage) SetIndex(idx *index.Index) error {
 	return err
 }
 
-func (s *IndexStorage) Index() (*index.Index, error) {
+func (s *IndexStorage) Index() (i *index.Index, err error) {
 	idx := &index.Index{
 		Version: 2,
 	}
diff --git a/storage/filesystem/internal/dotgit/dotgit.go b/storage/filesystem/internal/dotgit/dotgit.go
index 027ef83..60d122f 100644
--- a/storage/filesystem/internal/dotgit/dotgit.go
+++ b/storage/filesystem/internal/dotgit/dotgit.go
@@ -375,7 +375,7 @@ func (d *DotGit) findPackedRefsInFile(f billy.File) ([]*plumbing.Reference, erro
 	return refs, s.Err()
 }
 
-func (d *DotGit) findPackedRefs() ([]*plumbing.Reference, error) {
+func (d *DotGit) findPackedRefs() (r []*plumbing.Reference, error error) {
 	f, err := d.fs.Open(packedRefsPath)
 	if err != nil {
 		if os.IsNotExist(err) {
@@ -676,7 +676,7 @@ func (d *DotGit) PackRefs() (err error) {
 	// Gather all refs using addRefsFromRefDir and addRefsFromPackedRefs.
 	var refs []*plumbing.Reference
 	seen := make(map[plumbing.ReferenceName]bool)
-	if err := d.addRefsFromRefDir(&refs, seen); err != nil {
+	if err = d.addRefsFromRefDir(&refs, seen); err != nil {
 		return err
 	}
 	if len(refs) == 0 {
@@ -684,7 +684,7 @@ func (d *DotGit) PackRefs() (err error) {
 		return nil
 	}
 	numLooseRefs := len(refs)
-	if err := d.addRefsFromPackedRefsFile(&refs, f, seen); err != nil {
+	if err = d.addRefsFromPackedRefsFile(&refs, f, seen); err != nil {
 		return err
 	}
 
@@ -701,7 +701,7 @@ func (d *DotGit) PackRefs() (err error) {
 
 	w := bufio.NewWriter(tmp)
 	for _, ref := range refs {
-		_, err := w.WriteString(ref.String() + "\n")
+		_, err = w.WriteString(ref.String() + "\n")
 		if err != nil {
 			return err
 		}
diff --git a/storage/filesystem/internal/dotgit/dotgit_setref.go b/storage/filesystem/internal/dotgit/dotgit_setref.go
index c732c9f..d27c1a3 100644
--- a/storage/filesystem/internal/dotgit/dotgit_setref.go
+++ b/storage/filesystem/internal/dotgit/dotgit_setref.go
@@ -9,7 +9,7 @@ import (
 	"gopkg.in/src-d/go-git.v4/utils/ioutil"
 )
 
-func (d *DotGit) setRef(fileName, content string, old *plumbing.Reference) error {
+func (d *DotGit) setRef(fileName, content string, old *plumbing.Reference) (err error) {
 	// If we are not checking an old ref, just truncate the file.
 	mode := os.O_RDWR | os.O_CREATE
 	if old == nil {
diff --git a/storage/filesystem/object.go b/storage/filesystem/object.go
index 9f1c5ef..26190fd 100644
--- a/storage/filesystem/object.go
+++ b/storage/filesystem/object.go
@@ -55,7 +55,7 @@ func (s *ObjectStorage) requireIndex() error {
 	return nil
 }
 
-func (s *ObjectStorage) loadIdxFile(h plumbing.Hash) error {
+func (s *ObjectStorage) loadIdxFile(h plumbing.Hash) (err error) {
 	f, err := s.dir.ObjectPackIdx(h)
 	if err != nil {
 		return err
@@ -94,7 +94,7 @@ func (s *ObjectStorage) PackfileWriter() (io.WriteCloser, error) {
 }
 
 // SetEncodedObject adds a new object to the storage.
-func (s *ObjectStorage) SetEncodedObject(o plumbing.EncodedObject) (plumbing.Hash, error) {
+func (s *ObjectStorage) SetEncodedObject(o plumbing.EncodedObject) (h plumbing.Hash, err error) {
 	if o.Type() == plumbing.OFSDeltaObject || o.Type() == plumbing.REFDeltaObject {
 		return plumbing.ZeroHash, plumbing.ErrInvalidType
 	}
@@ -113,11 +113,11 @@ func (s *ObjectStorage) SetEncodedObject(o plumbing.EncodedObject) (plumbing.Has
 
 	defer ioutil.CheckClose(or, &err)
 
-	if err := ow.WriteHeader(o.Type(), o.Size()); err != nil {
+	if err = ow.WriteHeader(o.Type(), o.Size()); err != nil {
 		return plumbing.ZeroHash, err
 	}
 
-	if _, err := io.Copy(ow, or); err != nil {
+	if _, err = io.Copy(ow, or); err != nil {
 		return plumbing.ZeroHash, err
 	}