Re: [Monotone-devel] Re: how to merge trees

[Nathaniel Smith]

On Tue, Aug 16, 2005 at 01:31:23PM +0100, Bruce Stephens wrote:
> Nathaniel Smith <address@hidden> writes:
> >   -- once files are dead, they stay dead.  If some revision R is a
> >      descendent of B, and R does not contain the file, that file will
> >      not be contained in any descendent of R.
> 
> Doesn't the second of those make deletion rather too sticky?
> Specifically I'm imagining forking at R (or somewhere later), and in
> one branch the file gets deleted, but in the other it doesn't.  
> 
> If I understand everything correctly, I must choose to kill the file
> in a subsequent merge (since the merge is a descendant of both
> branches).  But surely that can't be so, so what am I
> misunderstanding?  

It does make deletion rather too sticky.  You're not misunderstanding.

(You can, of course, create a new file with the same name, in the
merged version.)

OTOH, it is the same model we've always had, and this version of it
actually works :-).  (I'm coming to respect "works" a _lot_ when it
comes to merge algorithms; it turns out that, at least as of
recently, we just had, like... none that did.)  So, baby steps...
"resurrection" is a non-trivial thing to support correctly.  For the
reasons you mention, I'd like to support it anyway... but I don't want
to until I can be confident we have a good representation that can be
handled safely.

-- Nathaniel

-- 
"...All of this suggests that if we wished to find a modern-day model
for British and American speech of the late eighteenth century, we could
probably do no better than Yosemite Sam."