Eli, Michael, thanks for the review.

> A better approach would be to prepend "GIT_OPTIONAL_LOCKS=0" in `process-environment'.

Thanks for the suggestion, I am attaching version 2 of the patch which
implements this suggestion.

> > Adding to the discussion:
> > * Dmitry Gutov, because he is the maintainer for lisp/vc/* .
> > * Eli Zaretskii and Michael Albinus, because they participated in the discussion on this bug before.
>
> Thanks, but there's no need to add me: I read all the messages sent to
> the bug list.

OK, I've removed you from the addressees. I'm not sure if I should do
the same for others, so I left Dmitry and Michael in CC.