Re: cc/cherry-pick-ff (Re: What's cooking in git.git (Mar 2010, #04; Tue, 16))

[Christian Couder <chriscool@tuxfamily.org>]

On Saturday 20 March 2010 15:20:03 Junio C Hamano wrote:
> Christian Couder <chriscool@tuxfamily.org> writes:
> > ... if we implement "git cherry-pick A..B", and if many people
> > start to use it, then perhaps it will make sense for --ff to become the
> > default.
> 
> That doesn't make any sense to me.
> 
> Think why you are saying A..B, with an explicit "A".
> 
> It is because you know it is different from HEAD; otherwise you would have
> done "git merge B"---slurp all changes between HEAD..B, which would be
> equivalent to "cherry-pick --ff HEAD..B".

I think that some people might avoid "git merge" altogether just because they 
may not be confident with merges and prefer linear histories.

They may also prefer "git cherry-pick A..B" over "git rebase" or "git rebase -
i" because it may be simpler for them to understand.

> As an ingredient for use of scripts that do not want to check (even if
> they could) if it is dealing with a corner case in which the commit a
> change is being applied to happens to be the commit the change in question
> is based on, being able to say --ff would make sense (as your patch series
> showed, it helped to lose several lines from the rebase-i implementation).
> The end user may not bother to count commits, and being able to ff earlier
> parts of "rebase -i HEAD~20" when the first "edit" appears after many
> "pick" would help (and that was why "rebase -i" internally had ff logic).
> 
> But running cherry-pick as the top-level operation is a conscious act of
> "I want to replay the change done by that one", and it would be utterly
> confusing if it fast-forwarded by default.  I agree with Jonathan that it
> will never be default.

Well, I think it is difficult to predict how and how much people will use "git 
cherry-pick A..B", and if after using it they will want fast forwarding by 
default to be consistent between "git cherry-pick" and "git merge" or if they 
won't care.

Best regards,
Christian.