--- modules/aaa/mod_authz_host.c.orig	2008-04-29 10:54:56.000000000 +0300
+++ modules/aaa/mod_authz_host.c	2008-04-29 11:39:17.000000000 +0300
@@ -42,6 +42,7 @@
 
 enum allowdeny_type {
     T_ENV,
+    T_NENV,
     T_ALL,
     T_IP,
     T_HOST,
@@ -123,10 +124,13 @@
     a->x.from = where;
     a->limited = cmd->limited;
 
-    if (!strncasecmp(where, "env=", 4)) {
+    if (!strncasecmp(where, "env=!", 5)) {
+        a->type = T_NENV;
+        a->x.from += 5;
+    }
+    else if (!strncasecmp(where, "env=", 4)) {
         a->type = T_ENV;
         a->x.from += 4;
-
     }
     else if (!strcasecmp(where, "all")) {
         a->type = T_ALL;
@@ -220,6 +224,12 @@
             }
             break;
 
+	case T_NENV:
+            if (!apr_table_get(r->subprocess_env, ap[i].x.from)) {
+                return 1;
+            }
+            break;
+
         case T_ALL:
             return 1;