Cloning a custom refspec does not work as expected

Hi,

I'm trying to clone a custom ref, avoiding the need to init && fetch manually. From reading [1] which says:

"Set a configuration variable in the newly-created repository; this takes effect immediately after the repository is initialized, but before the remote history is fetched or any files checked out. [...] This makes it safe, for example, to add additional fetch refspecs to the origin remote."

I'd assume that this would work:

$ git clone -c remote.origin.fetch=+refs/changes/*:refs/remotes/origin/changes/* https://gerrit.googlesource.com/git-repo

In fact, this *does* add the custom refs correct to .git/config, but they are not fetched during the clone. I can manually fix that by doing

$ cd git-repo $ git fetch

afterwards, but the whole point is to avoid exactly that separate step.

Is this a code bug or documentation bug?

I'm using git version 2.12.2.windows.2.

[1] https://git-scm.com/docs/git-clone#git-clone---configltkeygtltvaluegt