Re: [Evolution] Problems Splitting a Contact

[Adam Tauno Williams <awilliam whitemice org>]

On Sat, 2021-08-14 at 11:15 -0700, Jonathan Ryshpan wrote:
> I used to have a single contact for Bob and Wendy Doe, but now need
> two contacts, since they have different email addresses.  (Is this
> really necessary?  Comments welcome.) 

I don't understand what you are attempting to accomplish.  Why not
simply create a new contact and revise the old one?

>  I thought I'd duplicate the contact for "Bob & Wendy Doe); but this
> doesn't seem to be possible; file systems allow making copies of
> files to other files with similar names like say
> $ cp -a foo foo.bk

An addressbook is not a file system.

> So I thought I'd copy the contact for Bob&Wendy from my Personal
> contact list into another list called KeyNames, then edit the two
> copies so that the one in Personal is for Bob Doe and the one in
> KeyNames is for Wendy Doe; then copy the one in KeyNames (for Wendy
> Doe)  back to Personal.  This fails; I get a message warning of a UID
> conflict. 

Expected;  there's no event involved which would trigger reconstituting
the UID.  Frankly, as a WebDAV/CardDAV/CalDAV developer, this is a flaw
in vCard/vEvent/vToDo; there really is not a fully working scheme for
id'ing an object.

>  Well, thought I, I'll export the contact for Wendy Doe from KeyNames
> as a vcard and import this back into Personal.  This also fails for
> the same reason, but silently; if I edit the vcard to remove the
> line:
> UID:pas-id-419866BF000000A3
> everything works.

Expected.  If there is no UID one is created.

> I can't be the only person who has needed to do this kind of thing.
> Questions:  
> Would it be practical to allow contacts to be duplicated within the
> same list?

Sure, but the use case is very narrow.  This is easily enough
accomplished by the composite action of creating a new contact and
editing the old one.

Also, again, as a WedDAV/CardDAV, et al developer - don't create
compound contacts.  When you do so you are violating the object model,
which will eventually always have side effects.

> What is the function of the UID in a vcard?  Is it necessary?

It is the Unique ID of the vCard.  Yes it is necessary. And the vCard
is a 'dumb' object; it expects the client to manage the UID (which
sometimes isn't really possible).