( One more 'rollback' related bug import for today. This one is from RT#459).

####

If I try to rollback a depended-upon patch, darcs just complains:

--- clip ---
$ darcs changes
Wed Jul 6 14:12:49 EEST 2005 atehwa@sange.fi
* changed a line in foo

Wed Jul 6 14:12:32 EEST 2005 atehwa@sange.fi
* added a line into foo

Wed Jul 6 14:12:04 EEST 2005 atehwa@sange.fi
* adding foo
$ darcs rollback -p 'added a line into foo'

Skipping depended-upon patch:
Wed Jul 6 14:12:32 EEST 2005 atehwa@sange.fi
* added a line into foo
Cancelling rollback since no patch was selected.
--- clip ---

I think darcs should, instead, try to raise the patch as near to the
current moment as possible without conflicts, and then reverse-apply it.

#  	   	Thu Oct 06 17:02:00 2005  	jch - Correspondence added 	  	 

> If I try to rollback a depended-upon patch, darcs just complains:

> I think darcs should, instead, try to raise the patch as near to the
> current moment as possible without conflicts, and then reverse-apply it.

I agree. More precisely, the behaviour of rolling back A in (A,B) should
be the same as merging (A, B) with (A, A-1) (i.e. causing conflicts to
happen).

Even with the re-written rollback, it isn't possible to rollback a depended-upon
patch, unless the right sequence of patches in the dependency chain is also
selected to rollback. 

I can't decide whether it even makes sense to support trying to a rollback a
patch with the dependency chain for it, but for people who really want to, it
seems the UI could be improved to either list what the dependency chain is, or
work sort of "apt-get":

"Selecting this patch for rollback implies that the following patches which also
depend on it must also be rolled-back. Would you like to proceed?"

Anyway, this issue remains at "wishlist" status, so I would say other
improvements to darcs are higher priority, unless this is easy to address further.

On Fri, Jan 18, 2008 at 03:13:45AM -0000, Mark Stosberg wrote:
> Even with the re-written rollback, it isn't possible to rollback a depended-upon
> patch, unless the right sequence of patches in the dependency chain is also
> selected to rollback. 

I'll just point out that since we can rollback only a subset of the changes
in the selected patches, it's now possible (but awkward) to get the effect
of rolling back only a selected patch and the primitive patches that depend
on it.

And selecting the dependencies is actually quite easy simply by hitting 'w'
(or 'j') until you reach the patch you want to roll back.

David

Based on David's last comment it sounds like this "wish" is addressed somewhat
in the unstable branch, so I'm marking this as "resolved-in-unstable". 

Please re-test with a Darcs 2 build before considering re-opening the ticket.