Functionality regression from 1.4->1.5 in svn copy due to --use-merge-history changes

As a consequence of some changes associated with revsion r26495 in
libsvn_client/copy.c something that was possible in svn 1.4 can no
longer be accomplished in svn 1.5. This might be intentional, but I
suspect it was an accidental casualty:

In 1.4, this sequence of operations is possible:
- check out a module 'm1' into non-wc directory 'base'
- cwd to a directory completely outside of 'base' that is a working copy
for another path in the same repository as 'm1', above.
- svn cp 'base/m1' `pwd`

In 1.5, this sequence of operations fails with this message:
# svn: 'base' is not a working copy
# svn: Can't open file 'base/.svn/entries': No such file or directory

I don't know the propagate_mergeinfo_within_wc method well enough to say
what it's doing with src_access (acquired by calling svn_wc_adm_open3 on
'base' in my example) or to patch the code to change the behaviour.

My question is: is it necessary to get the parent directory's metadata
if it's not a working copy? Perhaps somebody more involved in the
--use-merge-history work could comment, please?

Attached is a script that -- with the substitution of the correct paths
for svn 1.4 and 1.4 binaries -- will demonstrate the issue directly.

Thank you for your time.

-- 
Chris Rose
Developer    Planet Consulting Group
(780) 577-8433
crose_at_planetci.com