quic: client should work when receives invalid preferred address

If we set `preferredAddressPolicy` to `accept` on `QuicClientSession`
but receives an invalid preferred address, e.g. we don't define
`preferredAddress` on the server, the `QuicClientSession` should still
work. Before this PR, the included test will cause segmetation fault.

PR-URL: nodejs#155
Reviewed-By: James M Snell <[email protected]>

Author: oyyd

src/node_quic_session.cc

@@ -2801,7 +2801,11 @@ bool QuicClientSession::SendConnectionClose() {
   sendbuf_.Cancel();
   QuicError error = GetLastError();
 
-  if (!WritePackets("client connection close - write packets"))
+  // If we're not already in the closing period,
+  // first attempt to write any pending packets, then
+  // start the closing period.
+  if (!IsInClosingPeriod() &&
+    !WritePackets("client connection close - write packets"))
     return false;
 
   ssize_t nwrite =
@@ -3223,8 +3227,8 @@ int QuicSession::OnSelectPreferredAddress(
     void* user_data) {
   QuicSession* session = static_cast<QuicSession*>(user_data);
   QuicSession::Ngtcp2CallbackScope callback_scope(session);
-  return session->SelectPreferredAddress(dest, paddr) ?
-      0 : NGTCP2_ERR_CALLBACK_FAILURE;
+  session->SelectPreferredAddress(dest, paddr);
+  return 0;
 }
 
 // Called by ngtcp2 when a stream has been closed for any reason.

src/node_quic_util.h

@@ -200,7 +200,7 @@ class SocketAddress {
     }
 
     char host[NI_MAXHOST];
-    if (uv_inet_ntop(af, binaddr, host, sizeof(host)) == 0)
+    if (uv_inet_ntop(af, binaddr, host, sizeof(host)) != 0)
       return false;
 
     addrinfo hints{};