Re: [PATCH] pull: abort if --ff-only is given and fast-forwarding is impossible

[Elijah Newren <newren@gmail.com>]

On Wed, Jul 14, 2021 at 1:37 AM Son Luong Ngoc <sluongng@gmail.com> wrote:
>
> Hi folks,
>
> I am out of the loop in this thread but I have been seeing strange behaviors
> with pull.rebase=true in the 'next' branch and also in the 'master'
> branch in recent days.

I'm not surprised it happens with recent versions, but I'd expect this
to have happened with older versions too.  Is this not reproducible
with git-2.32.0 or older git versions?

>   > git version
>   git version 2.32.0.432.gabb21c7263
>   > git config -l | grep pull
>   pull.rebase=true
>   pull.ff=false

So, you have conflicting configuration options set.  pull.ff=false
maps to --no-ff which is documented to create a merge.
pull.rebase=true maps to --rebase which says to run a rebase.

You probably want to drop one of these.

> But a git pull would still run fast-forward.
> Some of our users (including myself) rely on disabling fast-forward to emit the
> per-file change log summary after each git-pull
>
>   Updating 245f278cb729..5e8d960db7b3
>   Fast-forward
>    some/file/dir.ext         | 44 ++++++++++++++++++++++++++++++++++++++++++++
>    another/file/dir.ext     |  6 +++---
>   2 files changed, 47 insertions(+), 3 deletions(-)
>
> In a big, fast moving monorepo, this summary is a lot of noise and
> switching to pull.rebase=true
> used to be the way to turn it off. If the change is intended for next
> version release, is there a
> workaround for this?

Thanks for the report.  This particular commit has not yet been picked
up, not even in seen.  But it's a good example of how conflicting
configuration really ought to result in an error rather than randomly
picking one to trump, and suggests why we should complete the patch.

However, since I'm commenting on this and the stat information appears
to be important to you, note that there are also merge.stat and
rebase.stat configuration variables for controlling whether those are
shown at the end of merge and rebase operations.

Hope that helps,
Elijah