--- native/mod_proxy_cluster/mod_proxy_cluster.c	2011-03-14 17:11:42 UTC (rev 537)
+++ native/mod_proxy_cluster/mod_proxy_cluster.c	2011-03-16 10:43:02 UTC (rev 538)
@@ -1958,14 +1958,51 @@
  */
 static int proxy_cluster_canon(request_rec *r, char *url)
 {
+    char *host, *path;
+    char *search = NULL;
+    const char *err;
+    apr_port_t port = 0;
+
+    if (strncasecmp(url, "balancer:", 9) == 0) {
+        url += 9;
+    } else {
+        return DECLINED;
+    }
+
 #if HAVE_CLUSTER_EX_DEBUG
         ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_DEBUG, 0, r->server,
                     "proxy_cluster_canon url: %s", url);
 #endif
-    if (strncasecmp(url, "balancer:", 9) == 0) {
-        return OK;
+
+    /* do syntatic check.
+     * We break the URL into host, port, path, search
+     */
+    err = ap_proxy_canon_netloc(r->pool, &url, NULL, NULL, &host, &port);
+    if (err) {
+        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
+                      "error parsing URL %s: %s",
+                      url, err);
+        return HTTP_BAD_REQUEST;
     }
-    return DECLINED;
+    /*
+     * now parse path/search args, according to rfc1738:
+     * process the path. With proxy-noncanon set (by
+     * mod_proxy) we use the raw, unparsed uri
+    */
+    if (apr_table_get(r->notes, "proxy-nocanon")) {
+        path = url;   /* this is the raw path */
+    }
+    else {
+        path = ap_proxy_canonenc(r->pool, url, strlen(url), enc_path, 0,
+                                 r->proxyreq);
+        search = r->args;
+    }
+    if (path == NULL)
+        return HTTP_BAD_REQUEST;
+
+    r->filename = apr_pstrcat(r->pool, "proxy:balancer://", host,
+            "/", path, (search) ? "?" : "", (search) ? search : "", NULL);
+    return OK;
 }
 
 /*