On Tue, Dec 6, 2016 at 7:58 PM, Junio C Hamano <gitster@xxxxxxxxx> wrote: > I was burned a few times with this in the past few years, but it did > not irritate me often enough that I didn't write it down. But I > think this is serious enough that deserves attention from those who > were involved. Yeah, I agree that we should do something about it. > A short reproduction recipe, using objects from git.git that are > publicly available and stable, shows how bad it is. > > $ git checkout v2.9.3^0 > > $ git cherry-pick 0582a34f52..a94bb68397 > ... see conflict, decide to give up backporting to > ... such an old fork point. > ... the git-prompt gives "|CHERRY-PICKING" correctly. > > $ git reset --hard v2.10.2^0 > ... the git-prompt no longer says "|CHERRY-PICKING" > > $ edit && git commit -m "prelim work for backporting" > [detached HEAD cc5a6a9219] prelim work for backporting > > $ git cherry-pick 0582a34f52..a94bb68397 > error: a cherry-pick or revert is already in progress > hint: try "git cherry-pick (--continue | --quit | --abort)" > fatal: cherry-pick failed > > $ git cherry-pick --abort > ... we come back to v2.9.3^0, losing the new commit! > > The above shows two bugs. > > (1) The third invocation of "cherry-pick" with "--abort" to get rid > of the state from the unfinished cherry-pick we did previously > is necessary, but the command does not notice that we resetted > to a new branch AND we even did some other work there. This > loses end-user's work. > > "git cherry-pick --abort" should learn from "git am --abort" > that has an extra safety to deal with the above workflow. The > state from the unfinished "am" is removed, but the head is not > rewound to avoid losing end-user's work. > > You can try by replacing two instances of > > $ git cherry-pick 0582a34f52..a94bb68397 > > with > > $ git format-patch --stdout 0582a34f52..a94bb68397 | git am > > in the above sequence, and conclude with "git am--abort" to see > how much more pleasant and safe "git am --abort" is. Ok I will try to take a look at that next week. > (2) The bug in "cherry-pick --abort" is made worse because the > git-completion script seems to be unaware of $GIT_DIR/sequencer > and stops saying "|CHERRY-PICKING" after the step to switch to > a different state with "git reset --hard v2.10.2^0". If the > prompt showed it after "git reset", the end user would have > thought twice before starting the "prelim work". I am not used to hacking the prompt or completion scripts, so I would appreciate if someone else could do it. Thanks, Christian.