explain uncommit to me please

[Chris Hecker]

Thanks for the replies, folks.  A couple questions:

> Yes, it's still in that repository. IIRC under some conditions it
> can eventually get garbage collected, and it won't be added to a
> "bzr branch" off that branch, so if you delete that repository or it
> gets garbage collected, it's gone forever.

Is there any way to get a list of these?

> Do you need to understand it?

Since when has that ever stopped anybody from trying to understand 
something?  :)

Chris


On 2010/08/15 07:31, Stephen J. Turnbull wrote:
> Chris Hecker writes:
>
>   >  I just used bzr uncommit for the first time tonite, and I feel a
>   >  little dirty.  :)
>
> No, you're pure and clean.  Using uncommit in the privacy of your own
> repo is like getting into your private jacuzzi naked.
>
>   >  What happens to that revision in the branch?
>
> It disappears.  It's not technically part of the branch any more.
>
>   >  It's still got a revid, so it's in there somewhere?
>
> Yes, it's still in that repository.  IIRC under some conditions it can
> eventually get garbage collected, and it won't be added to a "bzr
> branch" off that branch, so if you delete that repository or it gets
> garbage collected, it's gone forever.
>
>   >  If I try to log -r revid:blah I hit the crash bug referenced here
>   >  (https://bugs.launchpad.net/ubuntu/+source/bzr/+bug/409266).
>
> That's a bug.  It should work.
>
> Do you crash if you do
>
> bzr merge revid:blah
>
> ?  If not, as long as you haven't done any commits or changed your
> workspace since the uncommit, that should undo the uncommit.  (The
> other cases should also work, but describing what should happen is
> more complex than I want to deal with.)
>
>   >  What would have happened if I'd pushed to another branch before
>   >  uncommitting?
>
> That's like flashing the Prime Minister on national TV.  Dirty.  Don't
> do it, you could be arrested and charged with public indecency.  :-)
>
> Probably it wouldn't be a big deal in the scenario you describe,
> actually, but it can be quite confusing if you try to push again to
> that branch after that.  You won't be able to, without pulling the
> commit you uncommitted back into the branch where it was uncommitted,
> or uncommitting that commit from the other branch.  Neither of those
> operations will necessarily be easy or obvious to accomplish once the
> two branches have diverged a bit.
>
> And the other direction is much worse.  If you allow somebody else to
> pull from your branch, uncommit, then let them try to pull again,
> they're likely to get quite confused because they don't know anything
> about the uncommit.
>
>   >  I have a feeling this has something to do with multiple heads or
>
> Exactly.
>
>   >  something like that, that I don't really understand since I'm
>   >  pretty new to dvcs.
>
> Do you need to understand it?  The rule is very simple: don't uncommit
> if the commit(s) involved have been merged (pushed, pulled) to another
> branch, *especially* not if it's not your branch.  (Like any good rule
> there are interesting exceptions, but again I'm too lazy to explain
> them. :-)
>
>