attempt to fix #493 by keeping io_service running while there are still peer connections

ChangeLog

@@ -56,6 +56,7 @@ release 0.14.3
 	  or checking, to maintain stats and renamed files
 	* Don't try IPv6 on windows if it's not installed
 	* move_storage fix
+	* fixed potential crash on shutdown
 
 release 0.14.2
 

include/libtorrent/peer_connection.hpp

@@ -621,6 +621,10 @@ namespace libtorrent
 		void on_disk_write_complete(int ret, disk_io_job const& j
 			, peer_request r, boost::shared_ptr<torrent> t);
 
+		// keep the io_service running as long as we
+		// have peer connections
+		io_service::work m_work;
+
 		// the time when we last got a part of a
 		// piece packet from this peer
 		ptime m_last_piece;

src/peer_connection.cpp

@@ -76,6 +76,7 @@ namespace libtorrent
 #endif
 		  m_ses(ses)
 		, m_max_out_request_queue(m_ses.settings().max_out_request_queue)
+		, m_work(ses.m_io_service)
 		, m_last_piece(time_now())
 		, m_last_request(time_now())
 		, m_last_incoming_request(min_time())
@@ -193,6 +194,7 @@ namespace libtorrent
 #endif
 		  m_ses(ses)
 		, m_max_out_request_queue(m_ses.settings().max_out_request_queue)
+		, m_work(ses.m_io_service)
 		, m_last_piece(time_now())
 		, m_last_request(time_now())
 		, m_last_incoming_request(min_time())