From 8447086c59184a2e519ff7e4f75097fed64c1a35 Mon Sep 17 00:00:00 2001
From: zzz <zzz@i2pmail.org>
Date: Tue, 30 Mar 2021 07:14:35 -0400
Subject: [PATCH] Transport: Fix NTCP removing IPv4 address when SSU removes
 IPv6 address

---
 .../net/i2p/router/transport/CommSystemFacadeImpl.java    | 8 +++-----
 .../java/src/net/i2p/router/transport/TransportUtil.java  | 2 ++
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/router/java/src/net/i2p/router/transport/CommSystemFacadeImpl.java b/router/java/src/net/i2p/router/transport/CommSystemFacadeImpl.java
index 61d988db3..722df0de6 100644
--- a/router/java/src/net/i2p/router/transport/CommSystemFacadeImpl.java
+++ b/router/java/src/net/i2p/router/transport/CommSystemFacadeImpl.java
@@ -323,21 +323,19 @@ public class CommSystemFacadeImpl extends CommSystemFacade {
         if (ip != null || port > 0)
             _manager.externalAddressReceived(Transport.AddressSource.SOURCE_SSU, ip, port);
         else
-            notifyRemoveAddress(false);
+            notifyRemoveAddress(udpAddr);
     }
 
     /** 
      *  Tell other transports our address changed
      *
-     *  @param address non-null; but address's host/IP may be null
+     *  @param address may be null; or address's host/IP may be null
      *  @since 0.9.20
      */
     @Override
     public void notifyRemoveAddress(RouterAddress address) {
         // just keep this simple for now, multiple v4 or v6 addresses not yet supported
-        notifyRemoveAddress(address != null &&
-                            address.getIP() != null &&
-                            address.getIP().length == 16);
+        notifyRemoveAddress(address != null && TransportUtil.isIPv6(address));
     }
 
     /** 
diff --git a/router/java/src/net/i2p/router/transport/TransportUtil.java b/router/java/src/net/i2p/router/transport/TransportUtil.java
index e00f094f0..2e4565d20 100644
--- a/router/java/src/net/i2p/router/transport/TransportUtil.java
+++ b/router/java/src/net/i2p/router/transport/TransportUtil.java
@@ -124,6 +124,8 @@ public abstract class TransportUtil {
     /**
      *  Addresses without a host (i.e. w/introducers)
      *  are assumed to be IPv4 unless a '6' cap is present
+     *
+     *  @param addr non-null
      */
     public static boolean isIPv6(RouterAddress addr) {
         // do this the fast way, without calling getIP() to parse the host string