vendor: update go-git to keybase/go-git master

This includes all the review changes requested from the go-git devs
for the garbage collection code.  They wanted to split off several of
the new methods into optional interfaces, which makes it a little more
complicated for us to build a "passthrough" storage layer.

Author: strib

libgit/ephemeral_git_config_with_fixed_pack_window.go

@@ -6,6 +6,7 @@ package libgit
 
 import (
 	"io"
+	"time"
 
 	gogitcfg "gopkg.in/src-d/go-git.v4/config"
 	"gopkg.in/src-d/go-git.v4/plumbing"
@@ -20,6 +21,8 @@ type ephemeralGitConfigWithFixedPackWindow struct {
 	storage.Storer
 	initer     storer.Initializer
 	pfWriter   storer.PackfileWriter
+	los        storer.LooseObjectStorer
+	pos        storer.PackedObjectStorer
 	packWindow uint
 }
 
@@ -53,6 +56,39 @@ func (e *ephemeralGitConfigWithFixedPackWindow) SetConfig(c *gogitcfg.Config) (
 	return nil
 }
 
+// ForEachObjectHash implements the `storer.LooseObjectStorer` interface.
+func (e *ephemeralGitConfigWithFixedPackWindow) ForEachObjectHash(
+	f func(plumbing.Hash) error) error {
+	return e.los.ForEachObjectHash(f)
+}
+
+// LooseObjectHash implements the `storer.LooseObjectStorer` interface.
+func (e *ephemeralGitConfigWithFixedPackWindow) LooseObjectTime(
+	h plumbing.Hash) (time.Time, error) {
+	return e.los.LooseObjectTime(h)
+}
+
+// DeleteLooseObject implements the `storer.LooseObjectStorer` interface.
+func (e *ephemeralGitConfigWithFixedPackWindow) DeleteLooseObject(
+	h plumbing.Hash) error {
+	return e.los.DeleteLooseObject(h)
+}
+
+// ObjectPacks implements the `storer.PackedObjectStorer` interface.
+func (e *ephemeralGitConfigWithFixedPackWindow) ObjectPacks() (
+	[]plumbing.Hash, error) {
+	return e.pos.ObjectPacks()
+}
+
+// DeleteOldObjectPackAndIndex implements the
+// `storer.PackedObjectStorer` interface.
+func (e *ephemeralGitConfigWithFixedPackWindow) DeleteOldObjectPackAndIndex(
+	h plumbing.Hash, t time.Time) error {
+	return e.pos.DeleteOldObjectPackAndIndex(h, t)
+}
+
 var _ storage.Storer = (*ephemeralGitConfigWithFixedPackWindow)(nil)
 var _ storer.Initializer = (*ephemeralGitConfigWithFixedPackWindow)(nil)
 var _ storer.PackfileWriter = (*ephemeralGitConfigWithFixedPackWindow)(nil)
+var _ storer.LooseObjectStorer = (*ephemeralGitConfigWithFixedPackWindow)(nil)
+var _ storer.PackedObjectStorer = (*ephemeralGitConfigWithFixedPackWindow)(nil)

libgit/repo.go

@@ -808,11 +808,16 @@ func NeedsGC(storage storage.Storer, options GCOptions) (
 	doPackRefs = numLooseRefs > options.MaxLooseRefs
 
 	if options.PruneMinLooseObjects >= 0 {
+		los, ok := storage.(storer.LooseObjectStorer)
+		if !ok {
+			panic("storage is unexpectedly not a LooseObjectStorer")
+		}
+
 		// Count the number of loose objects that are older than the
 		// expire time, to see if pruning is needed.
 		numLooseMaybePrune := 0
-		err = storage.ForEachObjectHash(func(h plumbing.Hash) error {
-			t, err := storage.LooseObjectTime(h)
+		err = los.ForEachObjectHash(func(h plumbing.Hash) error {
+			t, err := los.LooseObjectTime(h)
 			if err != nil {
 				return err
 			}
@@ -830,7 +835,12 @@ func NeedsGC(storage storage.Storer, options GCOptions) (
 		}
 	}
 
-	packs, err := storage.ObjectPacks()
+	pos, ok := storage.(storer.PackedObjectStorer)
+	if !ok {
+		panic("storage is unexpectedly not a PackedObjectStorer")
+	}
+
+	packs, err := pos.ObjectPacks()
 	if err != nil {
 		return false, 0, false, false, 0, err
 	}
@@ -909,6 +919,8 @@ func GCRepo(
 		storage,
 		fsStorage.(storer.Initializer),
 		fsStorage.(storer.PackfileWriter),
+		fsStorage.(storer.LooseObjectStorer),
+		fsStorage.(storer.PackedObjectStorer),
 		10,
 	}