* subversion/bindings/swig/python/svn/core.py   (svn_pool_destroy): Followup to r17639. Check more carefully whether the   application_pool is valid before allowing child pools to be destroyed.
* subversion/bindings/swig/python/svn/core.py
  (svn_pool_destroy): Followup to r17639. Check more carefully whether the
  application_pool is valid before allowing child pools to be destroyed.

NOTE: Fixes warnings about assertion failures reported during garbage
      collection when running Trac 0.9.x in CGI mode. See
      http://projects.edgewall.com/trac/ticket/2472

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion