Backport from HEAD:

* server/util.c (ap_resolve_env): Rewrite to avoid buffer overflows.

Submitted by: Andr�� Malo
Reviewed by: jorton, mjc


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/APACHE_2_0_BRANCH@105131 13f79535-47bb-0310-9956-ffa450edef68