Failure to resolve deltas when PlainClone or Fetching from a new AWS CodeCommit repository

[ga-paul-t]

When attempting to clone a newly created repository in AWS CodeCommit, that for example only contains a single commit, the following error is encountered:

reference delta not found

The following code is used to perform the clone:

repo, err := git.PlainClone(dir, false, &git.CloneOptions{
    URL:           url,
    ReferenceName: plumbing.NewBranchReferenceName("main"),
    Tags:          git.AllTags,
    SingleBranch:  true,
    Depth:         1,
})

I never encounter this issue when cloning from another source control system like Github

[ga-paul-t]

I have tried it with a few more CodeCommit repositories, and I can confirm that it doesn't always fail

[ga-paul-t]

Looking in the parser.go file, I can see where the External Reference is identified that ultimately results in the error being returned. However, the comment denotes that an external reference in a think pack file must be resolved. Looking through the source file I see no reference to that resolution ever taking place.

case plumbing.REFDeltaObject:
	delta = true
	parent, ok := p.oiByHash[oh.Reference]
	if !ok {
		// can't find referenced object in this pack file
		// this must be a "thin" pack.
		parent = &objectInfo{ //Placeholder parent
			SHA1:        oh.Reference,
			ExternalRef: true, // mark as an external reference that must be resolved
			Type:        plumbing.AnyObject,
			DiskType:    plumbing.AnyObject,
		}
		p.oiByHash[oh.Reference] = parent
	}
	ota = newDeltaObject(oh.Offset, oh.Length, t, parent)
	parent.Children = append(parent.Children, ota)

[ga-paul-t]

Looking through pull requests that are still open I have found a resolution that addresses this issue. I have tried it out with many different CodeCommit repositories and Github repositories, and it behaves as intended. A clone is successful with no reference delta error being returned.

#111

Any reason why this PR was never merged?

[pjbgf]

Closing as this was closed as part of #392 / #484.