Merge.bases only returns one Oid

How do you get multiple Oid out of an an Oid array? The Oids don't seems to be indexes, a call to oidarray.ids() returns one Oid, and multiple calls return the same Oid.

Setup:

git init
git commit --allow-empty --message foo1
git checkout -b dev
git commit --allow-empty --message foo2
git checkout master
git commit --allow-empty --message foo3
git merge -m "first merge base" dev
git checkout dev
git merge -m "second merge base" master~1
git merge-base --all master dev
# cac0d9e9c4d20fa2d09dcc9dfdbe44fcb5ad60d3
# 986123894e73887c35a1ee8294e9a17f1536144d

Script:

'use strict';

const git = require('nodegit');

function branchesOid(repo) {
  return Promise.all([
    repo.getReferenceCommit('master'),
    repo.getReferenceCommit('dev'),
  ]).then(commits => commits.map(c => c.id()));
}

git.Repository.open('.git').then(repo => {
  return branchesOid(repo).then(oid => git.Merge.bases(repo, ...oid))
}).then(oidarray => console.log(
  oidarray.count(),
  oidarray[0],
  oidarray[1],
  oidarray.ids(),
  oidarray.ids()
));

Result:

$ node merge-base.js
2 undefined undefined [Oid cac0d9e9c4d20fa2d09dcc9dfdbe44fcb5ad60d3] [Oid cac0d9e9c4d20fa2d09dcc9dfdbe44fcb5ad60d3]

Start by running the merge-base.js reproduction and tracing the git.Merge.bases entry point in the NodeGit bindings. Done means the returned collection exposes both merge-base Oids consistently, including through the access patterns shown in the report.