From 7681cb0887c54d07e85601de847f5b2a8bd1a356 Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Tue, 21 May 2013 06:44:11 -0600
Subject: [PATCH] fix `tcp-listen' error-message construction

---
 src/racket/src/network.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/racket/src/network.c b/src/racket/src/network.c
index 69d318e91d..b920b3b99a 100644
--- a/src/racket/src/network.c
+++ b/src/racket/src/network.c
@@ -2348,10 +2348,10 @@ tcp_listen(int argc, Scheme_Object *argv[])
       mz_freeaddrinfo(tcp_listen_addr);
     } else {
       scheme_raise_exn(MZEXN_FAIL_NETWORK,
-		       "tcp-listen: host not found\n"
+		       "tcp-listen: host lookup failed\n"
                        "  address: %s\n"
                        "  system error: %N",
-		       address, 1, err);
+		       address ? address : "#f", 1, err);
       return NULL;
     }
   }