Subject: looking for feedback on REDIRECT issue lc-57-noautoupdate

From: Julian Reschke <[email-masked]>
Date: Wed, 06 Oct 2004 19:38:31 +0200

Hi,

see 
(<http://greenbytes.de/tech/webdav/draft-ietf-webdav-redirectref-protocol-latest.html#rfc.issue.lc-57-noautoupdate>).

Back in 2000, Yaron Goland wrote that allowing a server to automatically 
update the target of a redirect ref can lead to surprising results.

I agree with this statement, but as a matter of fact there are systems 
that actually *do* behave this way (one of which being one we 
implemented...). Also, the REDIRECT spec IMHO empower users to create, 
modify and discover HTTP redirects without putting too many constraints 
on how they actually behave once they've been created.

Back in January I wrote:

"I don't think we can forbid that. This spec consists of (a) 
clarifications of how a server that supports redirects should behave for 
specific WebDAV methods, and (b) extensions to explicitly create them 
(or to apply a method to the redirect itself). As such, we shouldn't add 
any requirements that HTTP doesn't add. What we could do is (1) note why 
auto-update may be a bad idea, and possibly (2) define that redirects 
created by MKREDIRECTREF should not behave that way (or alternatively 
define more specific resource types)."

Today, I lean towards (1), that is we add a statement that redirects 
that change their link target automatically can cause confusion, but we 
do not forbid them.

Unless somebody objects, I'll make that change in the next draft.

Best regards, Julian

-- 
<green/>bytes GmbH -- http://www.greenbytes.de -- tel:+492512807760

---

From: Lisa Dusseault <[email-masked]>
Date: Wed, 6 Oct 2004 13:27:30 -0700

...
>  What we could do is (1) note why auto-update may be a bad idea, and 
> possibly (2) define that redirects created by MKREDIRECTREF should not 
> behave that way (or alternatively define more specific resource 
> types)."
>
> that change their link target automatically can cause confusion, but 
> we do not forbid them.
>
>
That looks reasonable; I tend to lean even more towards making server 
behavior consistent when possible, but if we can't do that in this case 
we can at least provide guidance.

Lisa

---

From: Julian Reschke <[email-masked]>
Date: Thu, 07 Oct 2004 15:56:39 +0200

Lisa Dusseault wrote:
> ....
>> behave that way (or alternatively define more specific resource types)."
>>

OK,

I added the following paragraph to the end of section 4:

    Implementation Note: Operations on the target of a redirect reference
    usually do not affect the redirect reference itself.  However,
    clients should not rely on this behaviour (for instance, some servers
    may update redirect references as a result of namespace operations on
    the reference's target).

(<http://greenbytes.de/tech/webdav/draft-ietf-webdav-redirectref-protocol-latest.html#rfc.issue.lc-57-noautoupdate>)

Best regards, Julian