Issue with global config defaults "user.useConfigOnly = true" + "pull.rebase = preserve" - "user.email"

[Dakota Hawkins <dakotahawkins@gmail.com>]

Hello,

I have a question which may be a bug (I'm a bit skeptical), but here goes:

In my global .gitconfig, I have "user.useConfigOnly = true" and
user.email isn't set there (I prefer to be forced to set it on a
per-repo basis, as I use different emails for work and personal
repos). I ALSO have "pull.rebase = preserve" set.

An example of the problem I have is with tools like golang (I filed an
issue there, they closed it and suggested the problem is with git or
my config: https://github.com/golang/go/issues/16516#issuecomment-235800085)
that use git to pull in package repos without any real user
interaction. When something like that runs a git pull for me (to
update a package repo) my global config makes it try to rebase, which
fails because git doesn't know who I am.

With golang, at least, there's no help setting-up all of its cloned
repos with my user information in local configs, it's a manual step
and I have to repeat it anytime anything decided to clone a new repo
to use as a package, so it's at least persistently frustrating. Hence
the golang bug, which I think is still a bug because they should
handle this better.

In those cases specifically, I never have local commits that differ
from the remote, so a "pull --ff-only" should leave me in the same
state as a "pull --rebase".

Is this a case of rebase trying to make sure it has enough information
for me to be a committer before knowing whether I even need to rewrite
any commits, and could/should that be avoided? Alternatively (or also)
could/should rebase detect that a fast-forward is possible and prefer
to do that instead?

I would not be surprised to learn that there's something I don't know
or haven't considered that explains why those things aren't really
do-able, but if that's the case I'd be interested to know what they
are (I'd love to go back to the golang people and tell them to re-open
my bug because there's nothing wrong with git).

Thanks for your time, and please let me know if you'd like any
additional information.

- Dakota Hawkins