--- httpd-2.4.9/modules/proxy/proxy_util.c	2014-06-06 16:25:57.928476514 -0400
+++ httpd-2.4.9/modules/proxy/proxy_util.c	2014-06-06 16:46:04.529531312 -0400
@@ -939,7 +939,7 @@ 
                     part = url;
                 }
             }
-            if (l1 >= l2 && strncasecmp(real, part, l2) == 0) {
+            if (l2 > 0 && l1 >= l2 && strncasecmp(real, part, l2) == 0) {
                 u = apr_pstrcat(r->pool, ent[i].fake, &part[l2], NULL);
                 return ap_is_url(u) ? u : ap_construct_url(r->pool, u, r);
             }