Comment 9 for bug 167907

> I cannot copy clones _with their origin_ to a document where there
> already exists an object with the same id as the clone origin object id.

This is fixed in SVN (see bug 165936).

As for fixing the original bug, we first need to decide what the correct behaviour is when clones are copied without the object they reference. Should we copy the referenced object anyway, and put it in 'defs' when we paste. Or should we just unlink the copied clones, so that they are no longer clones.