Re: override merge.ff = false using --ff-only

[Junio C Hamano <gitster@pobox.com>]

Matt McClure <matthewlmcclure@gmail.com> writes:

> I naively tried to override merge.ff = false using --ff-only on the
> command line. I expected that it would override the configured default
> and perform a fast-forward merge. Instead, it said:
>
>     $ git config -l | grep -F 'merge.ff'
>     merge.ff=false
>
>     $ git merge --ff-only foo
>     fatal: You cannot combine --no-ff with --ff-only.
>
> On the other hand, I see that --ff works just fine in the same initial state.
>
>     $ git merge --ff foo
>     Updating b869407..17b5495
>     Fast-forward
>     ...
>      4 files changed, 2 insertions(+), 5 deletions(-)
>
> Would it be better if --ff-only refused to merge only if the commits
> themselves prevented fast-forwarding?

In general it would be better if any --ff related command line
options made us ignore the configured default like merge.ff the user
may have in the repository, not just --ff-only vs merge.ff
combination, and your "On the other hand" demonstrates that it is
the case for --ff from the command line.

I do not offhand see why --ff-only should behave differently from
that expectation.