vendor: go-git: import IsDir() check for readReferenceFile()

[kevans91]

This fix has been accepted and merged upstream; the gist of the problem is
that readReferenceFile() must check that what it's been requested to read
isn't a directory. read() on a directory fd may work on some platforms (e.g.
FreeBSD), so readReferenceFile() would previously succeed at the earliest
point in a branch name (e.g. "feature" in "feature/myfeature") despite the
fact that this isn't a branch ref but a directory.

Fixes issue #9938

Signed-off-by: Kyle Evans [email protected]

PR notes:

• I've made this against release/v1.11 because that's where we observed the bug, but it's also applicable to master and I've verified that it cleanly cherry picks forward as well. Your contributing guidelines lead me to believe that I should target the branch it was observed on, apologies if this is incorrect and I'll create the PR against master instead.
• Corresponds to go-git/go-git@63967ab sans amendment to the tests introduced in the commit just prior to that one.

[lafriks]

vendored files should be updated using go get -u github.com/go-git/go-git/v5 and first targeted to master branch

[kevans91]

vendored files should be updated using go get -u github.com/go-git/go-git/v5 and first targeted to master branch

So we must wait for this commit to show up in an upstream release before it can be pulled into gitea? go get -u github.com/go-git/go-git/v5 doesn't bring it in at the moment, but I'm wholly unfamiliar with golang beyond the little bit of time I've spent on triage here.

re: branch, acknowledged, thanks!

[lafriks]

Yeah, we need to wait for go-git release

[kevans91]

Alright, thanks! We'll carry the patch locally until it can make its way here.