From d82df7e30ffb41f4df2aeeaa97e23e0e0212169f Mon Sep 17 00:00:00 2001
From: zelig <viktor.tron@gmail.com>
Date: Fri, 2 Jan 2015 18:54:59 +0000
Subject: [PATCH] if port is empty string, no listening

---
 eth/backend.go | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/eth/backend.go b/eth/backend.go
index 393254820b..352316ad54 100644
--- a/eth/backend.go
+++ b/eth/backend.go
@@ -142,12 +142,15 @@ func New(config *Config) (*Ethereum, error) {
 	}
 
 	eth.net = &p2p.Server{
-		Identity:   clientId,
-		MaxPeers:   config.MaxPeers,
-		Protocols:  protocols,
-		ListenAddr: ":" + config.Port,
-		Blacklist:  eth.blacklist,
-		NAT:        nat,
+		Identity:  clientId,
+		MaxPeers:  config.MaxPeers,
+		Protocols: protocols,
+		Blacklist: eth.blacklist,
+		NAT:       nat,
+	}
+
+	if len(config.Port) > 0 {
+		eth.net.ListenAddr = ":" + config.Port
 	}
 
 	return eth, nil