[darcs-users] Re: End-to-end validation [was: applying patches on windows]

[Tuomo Valkonen]

On 2005-11-09, David Roundy <droundy at darcs.net> wrote:
> On Tue, Nov 08, 2005 at 04:18:40PM +0100, Juliusz Chroboczek wrote:
>> The trouble with that is that Darcs plays the commutation game, which
>> invalidates any form of end-to-end hash.  The obvious solution would
>> be to compute hashes in a minimal context, but I'm not sure whether
>> that would be computationally feasible.
>
> I think I see.  You mean to store the patches as always, but to compute
> (and check) their hashes in a minimal context? That's a clever idea.
> Somehow I've been caught up on the "signed patch bundle" idea, which
> requires a new repository format, and didn't think of the idea of storing
> patches in their current format, but commuting them into another context
> for hashing.

This has, however, been suggested before (although perhaps not as 
explicitly):

http://www.abridgegame.org/pipermail/darcs-devel/2005-March/001388.html

    ... I've been thinking that it might be better to record patches in a
    "minimal context" ... This would enable support for signed patches and
    "freely floating patches". ... patches could also include an unsigned 
    version of themselves for "current/repository context" ... 

http://www.abridgegame.org/pipermail/darcs-devel/2005-March/001401.html

   ... which could be stored as a light patch-of-a-patch (the modifications
   should be just changes in line numbers, mergers, and so on, right?).

-- 
Tuomo