try ipv6 connections even after udp timeout

Also adds a test (auto_reconnect_test) which fails without this change.

1 files changed, 15 insertions, 0 deletions

diff --git a/toxcore/net_crypto.c b/toxcore/net_crypto.c
index 76cd27e7..a64ed970 100644
--- a/toxcore/net_crypto.c
+++ b/toxcore/net_crypto.c
@@ -634,6 +634,9 @@ static IP_Port return_ip_port_connection(Net_Crypto *c, int crypt_connection_id)
         v6 = 1;
     }
 
+    /* Prefer IP_Ports which haven't timed out to those which have.
+     * To break ties, prefer ipv4 lan, then ipv6, then non-lan ipv4.
+     */
     if (v4 && ip_is_lan(conn->ip_portv4.ip)) {
         return conn->ip_portv4;
     }
@@ -642,6 +645,18 @@ static IP_Port return_ip_port_connection(Net_Crypto *c, int crypt_connection_id)
         return conn->ip_portv6;
     }
 
+    if (v4 && net_family_is_ipv4(conn->ip_portv4.ip.family)) {
+        return conn->ip_portv4;
+    }
+
+    if (ip_is_lan(conn->ip_portv4.ip)) {
+        return conn->ip_portv4;
+    }
+
+    if (net_family_is_ipv6(conn->ip_portv6.ip.family)) {
+        return conn->ip_portv6;
+    }
+
     if (net_family_is_ipv4(conn->ip_portv4.ip.family)) {
         return conn->ip_portv4;
     }