minor ifdef tweaks and DHT logging

include/libtorrent/extensions/smart_ban.hpp

@@ -33,6 +33,8 @@ POSSIBILITY OF SUCH DAMAGE.
 #ifndef TORRENT_SMART_BAN_HPP_INCLUDED
 #define TORRENT_SMART_BAN_HPP_INCLUDED
 
+#ifndef TORRENT_DISABLE_EXTENSIONS
+
 #ifdef _MSC_VER
 #pragma warning(push, 1)
 #endif
@@ -58,5 +60,7 @@ namespace libtorrent
 	TORRENT_EXPORT boost::shared_ptr<torrent_plugin> create_smart_ban_plugin(torrent*, void*);
 }
 
+#endif // TORRENT_DISABLE_EXTENSIONS
+
 #endif // TORRENT_SMART_BAN_HPP_INCLUDED
 

src/kademlia/dht_tracker.cpp

@@ -643,7 +643,13 @@ namespace libtorrent { namespace dht
 
 		if (m_sock.send(addr, &m_send_buf[0], (int)m_send_buf.size(), ec, send_flags))
 		{
-			if (ec) return false;
+			if (ec)
+			{
+#ifdef TORRENT_DHT_VERBOSE_LOGGING
+				TORRENT_LOG(dht_tracker) << "==> " << addr << " DROPPED (" << ec.message() << ") " << log_line.str();
+#endif
+				return false;
+			}
 
 			// account for IP and UDP overhead
 			m_sent_bytes += m_send_buf.size() + (addr.address().is_v6() ? 48 : 28);