mergeinfo property

I've played with "svn propget svn:mergeinfo" and with "svn mergeinfo".
I've read
<http://www.collab.net/community/subversion/articles/merge-info.html>.
But there is still something I don't understand.

How do I know, for a given path at a given revision, which source path
(if any) has been merged into it ? In this case, I don't want the full
history of all the paths that have already been merged in that element
ancestry. Just a single source path (+ revision range) *IIF* the
requested revision actually is the result of a merge. The equivalent of
the "(from /bidon/trunk:42)" that you get from "svn log -v" in the case
of a copy.

Is there anything like it ?

TIA

Ph. A.

-- 
*Philippe Andersson*
Unix System Administrator
IBA Particle Therapy |
Tel: +32-10-475.983
Fax: +32-10-487.707
eMail: pan_at_iba-group.com
<http://www.iba-worldwide.com>
The contents of this e-mail message and any attachments are intended solely for 
the recipient (s) named above. This communication is intended to be and to 
remain confidential and may be protected by intellectual property rights. Any 
use of the information contained herein (including but not limited to, total or 
partial reproduction, communication or distribution of any form) by persons 
other than the designated recipient(s) is prohibited. Please notify the sender 
immediately by e-mail if you have received this e-mail by mistake and delete 
this e-mail from your system. E-mail transmission cannot be guaranteed to be 
secure or error-free. Ion Beam Applications does not accept liability for any 
such errors. Thank you for your cooperation.