Checking out a copied directory at a revision prior to the copy results in a checkout of the data before the copy. I would expect this to fail in the same way that attempting to update to an invalid revision fails.
Is this the intended behaviour? If so, shouldn't there be some message that your working copy is using a different location than requested?
> svn copy trunk mybranch -m 'copy test'
Committed revision 2
> svn co mybranch -r1 mybranch
> svn info mybranch
Relative URL: ^trunk
Checking out the branch at a valid revision then attempting to update to the earlier revision results in an error:
svn: E160005: Target path 'mybranch' does not exist
(I was attempting to checkout the revision given by 'Last Changed Rev' from 'svn info' on a child of a copied directory - it points at a revision before the copy, but that's a different discussion)
