plumbing: format/packfile, fix panic retrieving object hash.

In some cases the original data is not saved before it is cleaned
and forces a panic when it's needed.

The change adds ObjectToPack.CleanOriginal to be used to clean original
object instead of:

    object.Original = nil

Now when the Original data is freed because it's no longer in the pack
window a SetOriginal call is done to make sure that Size, Hash and Size
data is not lost.

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

1 files changed, 5 insertions, 0 deletions

diff --git a/plumbing/format/packfile/object_pack.go b/plumbing/format/packfile/object_pack.go
index 877581e..661278d 100644
--- a/plumbing/format/packfile/object_pack.go
+++ b/plumbing/format/packfile/object_pack.go
@@ -90,6 +90,11 @@ func (o *ObjectToPack) SetOriginal(obj plumbing.EncodedObject) {
 	}
 }
 
+// CleanOriginal sets Original to nil
+func (o *ObjectToPack) CleanOriginal() {
+	o.Original = nil
+}
+
 func (o *ObjectToPack) Type() plumbing.ObjectType {
 	if o.Original != nil {
 		return o.Original.Type()