Partially address issue #756:
Partially address issue #756:

* subversion/libsvn_wc/copy.c 
  (copy_file_administratively): Be stricter about disallowing copies
  of copies, and improve error message for that case.

Note that this doesn't fully resolve the issue.  The truly golden fix
is rather more complex, see the issue for details.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@842520 13f79535-47bb-0310-9956-ffa450edef68

wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion