On Thu, Dec 3, 2020 at 8:06 PM Junio C Hamano <gitster@xxxxxxxxx> wrote: > > Junio C Hamano <gitster@xxxxxxxxx> writes: > > > Junio C Hamano <gitster@xxxxxxxxx> writes: > > > >>> That would require changing the semantics of --ff-only, so that "git > >>> pull --no-rebase --ff-only" doesn't make sense (as --ff-only is > >>> overridden by --no-rebase). > >> > >> I do not think such a conclusion follows from "we do not want to use > >> the 'by default force the --ff-only' when the user chooses between > >> merge and rebase". Specifically, I do not agree with "as --ff-only > >> is overridden" in your statement. > > > > Ah, sorry, I mis-read your three lines above. > > ... > > And if we introduce a third-way, i.e. "we do not handle the case > > where you have your own development at all, this is only to maintain > > pristine copy from your upstream", and repurpose "--ff-only" for > > that purpose, yes, what you said above does make sense. At that > > point, there is no reason to disagree with "as --ff-only is > > overridden" part of your statement---in your new world, "--ff-only" > > is redesigned to act that way. > > Just to avoid misunderstanding, I only meant to say that the first > three lines I quoted is internally consistent (unlike the message I > was responding to, in which I said "I disagree---the conclusion does > not follow"). It no way means I think such a re-definition of what > "--ff-only" means is a great design. Yes, that's what I parsed. > What we want to see can be done without such backward incompatible > changes, e.g. declaring the combination of "--ff-only" and > "--[no-]rebase" incompatible and/or the last one wins, I would say, > and I suspect Alex's RFC was an attempt to make the first step in > that direction. It's debatable whether or not that is "backwards incompatible". Currently "--no-rebase --ff-only" fails if the merge is non-fast-forward. With the proposed change of semantics it would work. That's a change. > What is most missing in the current system is a fix for the way in > which "--rebase" interacts with "--ff-only". Immediately after > fetching, if our current branch is not a subset of what we fetched > from the other side, the command should die. Otherwise, it should > just rebase what we have (which is nothing) on top of the tip of the > history of the other side (which is to fast-forward our tip and the > working tree to their tip). Keep in mind the whole point of the changes: to make --ff-only the default. If you make "git pull --rebase --ff-only" fail if not-fast-forward, then "git pull --rebase" will fail if you make --ff-only the default. I don't know if I'm not doing a good job of stating that --rebase should override (and ignore) --ff-only, that's the way it should interact. Here it goes again. In short, this is the target behavior: * git pull --ff-only # fail unless fast-forward * git pull --merge --ff-only # ignore --ff-only * git pull --rebase --ff-only # ignore --ff-only > Another thing we would want to change is to make the "you must > choose between rebase and merge" trigger a lot more lazily. If our > side does not have our own development and their history is a > descendent of what we have, the user shouldn't have to choose. Only > when the history they have does not fast-forward, we have to abort > giving the "you must choose between the two" warning message. Yes, I already sent patches for that [1]. > When the user tells us to do rebase or merge, nothing (except that > "--ff-only" should prevent the rebase from going forward) should > have to be changed. If --ff-only prevents the rebase and the merge from going forward, then it cannot be the default. Maybe my last patch series can make things clearer [2]. Cheers. [1] https://lore.kernel.org/git/20201204061623.1170745-11-felipe.contreras@xxxxxxxxx/ [2] https://lore.kernel.org/git/20201204061623.1170745-1-felipe.contreras@xxxxxxxxx/T/ -- Felipe Contreras
