From: Jan Harkes <jaharkes@cs.cmu.edu>
Date: Fri, 20 Oct 2006 02:46:02 GMT
Subject: Re: [PATCH 2/2] Remove unused index tracking code.
Message-ID: <20061020024602.GF7162@delft.aura.cs.cmu.edu>
In-Reply-To: <7vd58nra64.fsf@assigned-by-dhcp.cox.net>

On Thu, Oct 19, 2006 at 07:30:27PM -0700, Junio C Hamano wrote:
> Jan Harkes <jaharkes@cs.cmu.edu> writes:
> 
> > I guess I'll grep through the mailinglists to try to figure out what
> > these OFS and REF deltas are and why they behave so differently
> > depending on their order in the pack.
> 
> It's been cooking in "next" branch for quite a while.

Ah yes, just went through the thread about the git-index-pack breaking on
64-bit systems and the back and forth about the possible complexity of
the new code.

> It is really simple:
>
>  - if the found union content matches with a reference union initialized
>    through the sha1 member then deltas[j].obj->type == OBJ_REF_DELTA
>    must be true.
>
>  - if the found union content matches with a reference union initialized
>    through the sha1 member then deltas[j].obj->type == OBJ_OFS_DELTA
>    must be true.
...

I guess one of these must be false.

But clearly this patch breaks those offset based delta's when we expand
random deltas in place.

Jan