use max hash size constant for all SHA byte arrays

Expanding on the introduction of the maxHashSize constant in
528473b, we can use this
in several other places as well for byte array initialization.

Author: chrisd8088

pack/index.go

@@ -7,7 +7,7 @@ import (
 	"io"
 )
 
-const maxHashSize = sha256.Size
+const MaxHashSize = sha256.Size
 
 // Index stores information about the location of objects in a corresponding
 // packfile.

pack/index_v1.go

@@ -13,7 +13,7 @@ type V1 struct {
 // Name implements IndexVersion.Name by returning the 20 byte SHA-1 object name
 // for the given entry at offset "at" in the v1 index file "idx".
 func (v *V1) Name(idx *Index, at int64) ([]byte, error) {
-	var sha [maxHashSize]byte
+	var sha [MaxHashSize]byte
 
 	hashlen := v.hash.Size()
 

pack/index_v2.go

@@ -13,7 +13,7 @@ type V2 struct {
 // Name implements IndexVersion.Name by returning the 20 byte SHA-1 object name
 // for the given entry at offset "at" in the v2 index file "idx".
 func (v *V2) Name(idx *Index, at int64) ([]byte, error) {
-	var sha [maxHashSize]byte
+	var sha [MaxHashSize]byte
 
 	hashlen := v.hash.Size()
 

pack/packfile.go

@@ -190,7 +190,7 @@ func (p *Packfile) findBase(typ PackedObjectType, offset, objOffset int64) (Chai
 	// We assume that we have to read at least an object ID's worth (the
 	// hash length in the case of a OBJ_REF_DELTA, or greater than the
 	// length of the base offset encoded in an OBJ_OFS_DELTA).
-	var sha [32]byte
+	var sha [MaxHashSize]byte
 	if _, err := p.r.ReadAt(sha[:hashlen], offset); err != nil {
 		return nil, baseOffset, err
 	}

tree.go

@@ -10,6 +10,8 @@ import (
 	"strconv"
 	"strings"
 	"syscall"
+
+	"github.com/git-lfs/gitobj/v2/pack"
 )
 
 // Tree encapsulates a Git tree object.
@@ -53,7 +55,7 @@ func (t *Tree) Decode(hash hash.Hash, from io.Reader, size int64) (n int, err er
 		n += len(fname)
 		fname = strings.TrimSuffix(fname, "\x00")
 
-		var sha [32]byte
+		var sha [pack.MaxHashSize]byte
 		if _, err = io.ReadFull(buf, sha[:hashlen]); err != nil {
 			return n, err
 		}