Re: COPY of a binding onto another binding of same resource

Lisa Dusseault wrote:

> 
> When a user does a COPY or MOVE from one binding to another binding to 
> the same resource, this should be flagged as an error.  Since this has 
> to interoperate with existing clients that won't look at the error body, 
> the status code would have to stand alone.  409 is already used for 
> non-existent parent collections, so that can't be reused.  Possibly 403 
> which in 2518 for COPY means "_ The source and destination URIs are the 
> same."

...btw, I disagree with the sentiment that specific new error conditions 
must use HTTP status codes different from any status code used 
previously for that operation (in fact, the whole point is that by 
sending the same status code like for another situation I can trigger 
the same error recovery/treatment on the client).

In particular, note that 409 can occur for many other reasons, and a 
client that somehow equates 409 with "parent collection does not exist" 
is plain broken (this is why it would be a good thing ifg RFC2518bis 
associated that with a specific precondition name).

The advantage of RFC3253's HTTP status code / DAV:error body extension 
is that existing clients will continue to see well-defined HTTP status 
codes (usually defined by RFC2616, not RFC2518), while new, 
WebDAV-specific clients can take advantage of additional information 
sent with the body (for instance, in ACL this enables the client to 
state which privilege was missing causing the 403 Access Denied).


Julian


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Received on Wednesday, 24 March 2004 16:51:19 UTC