Revision 1162852

  * mod_filter: FilterProvider conditions of type "resp=" (response headers)
    do not work for CGI, because headers_out are not populated. We need to use
    err_headers_out instead in this case. In trunk this is handled by ap_expr().
    Joe recently added fall back to err_headers_out to ap_expr and the proposed
    mod_filter patch is analogous to Joe's fix.
    The patch fixes the test suite failure for t/modules/filter.t.
    Trunk patch: http://svn.apache.org/viewvc?view=revision&revision=1090234
    2.2.x patch: http://people.apache.org/~rjung/patches/mod_filter-cgi-err_headers_out.patch
    +1: rjung, jorton, sf