From: Junio C Hamano <junkio@cox.net>
Date: Thu, 19 Jan 2006 18:24:15 GMT
Subject: Re: [QUESTION] about .git/info/grafts file
Message-ID: <7vwtgwdqk0.fsf@assigned-by-dhcp.cox.net>
In-Reply-To: <Pine.LNX.4.64.0601190842270.3240@g5.osdl.org>

Linus Torvalds <torvalds@osdl.org> writes:

>  - a full clone takes a long time. Git _could_ fairly easily have an 
>    extension to add a date specifier to clone too:
>
> 	git clone --since=1.month.ago <source> <dst>
>
>    and just leave any older stuff (you could always fetch it later), but 
>    we've just never done it. Maybe we should. It _should_ be pretty simple 
>    to do from a conceptual standpoint.

True, except some implementation details you forgot to mention
in your other message that you talked about upload-version.
Both commit walkers and git native transfer fundamentally
operate by trusting that our current refs are complete, which
makes "could always fetch it later" part a bit involved.

It fortunately would not be a rocket science.  We would need to
have a mode "do not trust our current refs are complete" with an
explicit command line option, or automatically fall back to that
mode when seeing the $GIT_DIR/info/grafts file has changed, and
revalidate the commit ancestry chain we have in a repository
cloned that way.