From 4d17e0132e67b237ec4d30a513af6c62d0bc954a Mon Sep 17 00:00:00 2001
From: arvidn <arvid@libtorrent.org>
Date: Wed, 25 Apr 2018 12:31:02 -0400
Subject: [PATCH] fix empty outgoing interfaces for UDP sockets

---
 include/libtorrent/aux_/session_udp_sockets.hpp |  3 ++-
 src/session_impl.cpp                            |  4 ++--
 src/session_udp_sockets.cpp                     | 10 ++++++++--
 3 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/include/libtorrent/aux_/session_udp_sockets.hpp b/include/libtorrent/aux_/session_udp_sockets.hpp
index b751382c4..5bc5959d2 100644
--- a/include/libtorrent/aux_/session_udp_sockets.hpp
+++ b/include/libtorrent/aux_/session_udp_sockets.hpp
@@ -89,7 +89,8 @@ namespace libtorrent { namespace aux {
 		std::vector<std::shared_ptr<outgoing_udp_socket>>::iterator
 		partition_outgoing_sockets(std::vector<listen_endpoint_t>& eps);
 
-		tcp::endpoint bind(socket_type& s, address const& remote_address) const;
+		tcp::endpoint bind(socket_type& s, address const& remote_address
+			, error_code& ec) const;
 
 		void update_proxy(proxy_settings const& settings);
 
diff --git a/src/session_impl.cpp b/src/session_impl.cpp
index fbeec2100..f85087bca 100644
--- a/src/session_impl.cpp
+++ b/src/session_impl.cpp
@@ -4988,8 +4988,8 @@ namespace aux {
 
 		if (is_utp(s))
 		{
-			auto ep = m_outgoing_sockets.bind(s, remote_address);
-			if (ep.port() != 0)
+			auto ep = m_outgoing_sockets.bind(s, remote_address, ec);
+			if (ep.port() != 0 || ec)
 				return ep;
 		}
 
diff --git a/src/session_udp_sockets.cpp b/src/session_udp_sockets.cpp
index 8ec281e34..2a63f1e43 100644
--- a/src/session_udp_sockets.cpp
+++ b/src/session_udp_sockets.cpp
@@ -32,6 +32,7 @@ POSSIBILITY OF SUCH DAMAGE.
 
 #include "libtorrent/aux_/session_udp_sockets.hpp"
 #include "libtorrent/aux_/session_impl.hpp"
+#include "libtorrent/error_code.hpp"
 
 namespace libtorrent { namespace aux {
 
@@ -63,9 +64,14 @@ namespace libtorrent { namespace aux {
 		});
 	}
 
-	tcp::endpoint outgoing_sockets::bind(socket_type& s, address const& remote_address) const
+	tcp::endpoint outgoing_sockets::bind(socket_type& s
+		, address const& remote_address, error_code& ec) const
 	{
-		TORRENT_ASSERT(!sockets.empty());
+		if (sockets.empty())
+		{
+			ec.assign(boost::system::errc::not_supported, generic_category());
+			return tcp::endpoint();
+		}
 
 		utp_socket_impl* impl = nullptr;
 		transport ssl = transport::plaintext;