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Re: DAV:cannot-copy-collection-version precondition for COPY

From: Werner Donné <werner.donne@re.be>
Date: Tue, 22 Aug 2006 22:24:25 +0200
Message-ID: <44EB67F9.30605@re.be>
To: Geoffrey M Clemm <geoffrey.clemm@us.ibm.com>
Cc: ietf-dav-versioning@w3.org

Geoff,

I thought that a version of a collection represented the state of
that collection at a certain point. So the version-controlled-binding-set,
which is a collection version property, contains the binding names
that correspond to the members of the collection at that version.
If collection /a has members b and c at a certain point, then the
version of the collection corresponding to this would have binding
names b and c.

Given a version of a VCR, a system can find that VCR. If our VCR is
collection /a and if we have binding names b and c in the collection
version, we can reconstruct /a/b and /a/c. Now we have enough to
create a new collection with members b and c.

I don't find that very strange. What is the difference between copying
a collection version to another collection, leading to a new version
controlled collection in the latter, and copying a version controlled
collection with a label header. Precondition must-select-version-in-history
in section 8.7 results in some collection version to be used for the
copy. I could also have specified that collection version directly in
the request URI.

Regards,

Werner.

Geoffrey M Clemm wrote:
> 
> It sounds like you are suggesting that the result of the copy depend on
> what is in the target of the copy?  That would be very strange "copy"
> behavior (i.e. the result of the copy should only depend on the source
> of the copy).  Collection versions are for use by "merge" and "update".
> 
> Cheers,
> Geoff
> 
> Werner Donné <werner.donne@re.be> wrote on 08/22/2006 10:59:59 AM:
> 
>> A collection version has the names of its version controlled bindings
>> and their version history. It is then possible to find the checked-in
>> version of the members, which is what is used also when a collection
>> is copied.
>>
>> Regards,
>>
>> Werner.
>>
>> Geoffrey M Clemm wrote:
>> >
>> > A collection version does not have enough information in it to produce a
>> > sensible copy, since it only records the version history of its members,
>> > not the versions.  So a collection version is useful for updating a
>> > configuration, but is not useful for creating a new configuration
>> > (that's what baselines are for).
>> >
>> > Cheers,
>> > Geoff
>> >
>> > ietf-dav-versioning-request@w3.org wrote on 08/22/2006 06:34:16 AM:
>> >
>> >>
>> >> Hi,
>> >>
>> >> Why should the request fail if the source is a collection version?
>> >> It seems to me that any version is as good as the checked-in version
>> >> to copy from.
>> >>
>> >> Regards,
>> >>
>> >> Werner.
>> >> --
>> >> Werner Donné  --  Re
>> >> Engelbeekstraat 8
>> >> B-3300 Tienen
>> >> tel: (+32) 486 425803   e-mail: werner.donne@re.be
>> >>
>>
>> --
>> Werner Donné  --  Re
>> Engelbeekstraat 8
>> B-3300 Tienen
>> tel: (+32) 486 425803   e-mail: werner.donne@re.be

-- 
Werner Donné  --  Re
Engelbeekstraat 8
B-3300 Tienen
tel: (+32) 486 425803	e-mail: werner.donne@re.be
Received on Tuesday, 22 August 2006 23:02:57 GMT

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