From: linux@horizon.com
Date: Sat, 09 Sep 2006 10:31:57 GMT
Subject: Re: Change set based shallow clone
Message-ID: <20060909103157.23388.qmail@science.horizon.com>

> If the out of order revisions are a small amount of the total then
> could be possible to have something like
> 
> git rev-list --topo-order --with-appended-fixups HEAD
> 
> Where, while git-rev-list is working _whithout sorting the whole tree
> first_, when finds an out of order revision stores it in a fixup-list
> buffer and *at the end* of normal git-rev-lsit the buffer is flushed
> to receiver, so that the drawing logic does not change and the out of
> order revisions arrive at the end, already packed, sorted and prepared
> by git-rev-list.

I don't think I understand your proposal.  The problem arises when
git-rev-list finds a commit that it should have listed before something
that it has already output.

Just for example:

Commit D: Ancestor B
Commit B: Ancestor A
Commit C: Ancestor B

Commit C is the problem, because if git-rev-list has already output B,
there's no way to back up and insert it in the right place.

How is waiting to output the already-behind-schedule commit C going
to help anything?  The idea in gitk is to rewind the layout algorithm
to before B was added, insert C, and replay from there.  This is
most efficient if C is encountered as soon after its correct place
as possible.