Subject: Re (2): I-D for WebDAV methods - APPEND and PATCH

From: [email-masked]
Date: Tue, 15 Aug 2006 23:33:59 +0200 (MEST)

Lisa Dusseault <[email-masked]> wrote:
> On Aug 4, 2006, at 12:05 AM, Suma Potluri wrote:
> > Hi Julian,
> > Thanks for your response. I wasn't aware of the earlier draft on  
> > PATCH by
> > Lisa Dusseault when I submitted this latest draft. I admit that I  
> > should
> > have done a little more research into it before submitting the new  
> > I-D. In
> > any case, I noticed that there hasn't been much activity in this area
> > since the past two years. I would be happy to collaboratively work  
> > with
> > Lisa Dusseault or anyone else that would be interested in these  
> > methods,
> > so that we could get something useful out of this.
> That would be great.  I've been letting the  PATCH document languish  
> waiting for some broader consensus for a resolution to the question  
> of what Content-Type means. That's the essential difference between  
> patch draft -05 and draft -06.  The changes made to 06 were inspired  
> by Jeff Mogul; I find his entity/instance model elegant in its  
> resolution of a few modeling problems, even if it wasn't how HTTP was  
> initially intended to be modeled.  However, Roy Fielding has objected  
> to draft -06 and to Mogul's model and I didn't see a clear consensus  
> which way to go.
After reading the old drafts and also Roys comments:
- I would definitly go with Content-Type to give the diff algorithm.
  Please no additional header :-(
- Find a simple mandatory binary diff which is free of IPR.
  I'm no lawyer, but could it help to use a binary diff I use
  for years now in an esoteric system called Oberon from ETH Zuerich.
  Nobody complained about it in all these years :-)
  Only joking, but can anybody tell me what the problem with gdiff is ?
- NO APPEND.
Perhaps Lisa and Suma could collaborate and provide a new draft.
And if somebody decides to go to another list. Please tell me to subscribe
to it :-)
OTOH I think that PATCH has a special importance in the context of
versioning. So perhaps it could be a good idea to find a rough consensus
here before going to the HTTP jungle.

Cheers, Edgar

---

From: Lisa Dusseault <[email-masked]>
Date: Tue, 15 Aug 2006 15:39:24 -0700

>   Nobody complained about it in all these years :-)

Can you try to verify its licensing status?  It would be great to  
have an unburdened generally-useful diff algorithm.

There are also two possible XML diff algorithms: Jara Urpalainen's,  
and Adrian Mouat's.  Both have been published as Internet-Drafts in  
the past.

>   Only joking, but can anybody tell me what the problem with gdiff  

The gdiff algorithm doesn't have a Content-Type.  To register a  
content-type, I think we'd have to publish an Internet-Draft: see  
http://www.alvestrand.no/pipermail/ietf-types/2004-September/ 
000410.html.   I believe we'd be OK publishing an I-D with just the  
IANA form and a reference to the W3C note, but I haven't gotten  
around to that yet.  Help welcome.

(BTW in hunting down this reference I found the time-range that saw  
lots of discussion on the HTTP WG list on the PATCH stuff: http:// 
lists.w3.org/Archives/Public/ietf-http-wg/2004AprJun/ and http:// 
lists.w3.org/Archives/Public/ietf-http-wg/2004JulSep/)

Another candidate is VCDIff, but it's unclear how broadly VCDIff may  
be used. See <http://www.ietf.org/ietf/IPR/ATT-draft-korn-vcdiff>,  
and note it's limited to HTTP1.1.  Does that mean RFC2616 only or  
does it include specs that extend HTTP 1.1 while retaining that  
protocol version header? IANAL.

> here before going to the HTTP jungle.
Thanks for the comments.
Lisa

---

From: "Suma Potluri" <[email-masked]>
Date: Tue, 15 Aug 2006 16:18:19 -0700 (PDT)

Hi Lisa,

I am glad to hear your take on this issue again.

> around to that yet.  Help welcome.

I believe that we could include the registration information for the new
MIME types as a separate section in the PATCH I-D itself. But, I'd like to
hear any comments about using the normal-diff as the patch format for text
files. Once we reach a consensus on the patch formats, I could work on
registering the new MIME types and publishing the draft.

>> here before going to the HTTP jungle.

Thanks,
-Suma