From d0dab83104f8107e361892ac8308632b5fdfd10f Mon Sep 17 00:00:00 2001
From: Arvid Norberg <arvid@libtorrent.org>
Date: Sat, 2 Oct 2010 21:01:11 +0000
Subject: [PATCH] potential fix for long standing invariant check failure

---
 src/peer_connection.cpp | 26 ++++++++++++++++++++++----
 src/policy.cpp          |  1 +
 2 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/src/peer_connection.cpp b/src/peer_connection.cpp
index 964186a4f..0b42d9a05 100644
--- a/src/peer_connection.cpp
+++ b/src/peer_connection.cpp
@@ -808,6 +808,8 @@ namespace libtorrent
 		}
 #endif
 		TORRENT_ASSERT(!m_ses.has_peer(this));
+		TORRENT_ASSERT(m_request_queue.empty());
+		TORRENT_ASSERT(m_download_queue.empty());
 #ifdef TORRENT_DEBUG
 		for (aux::session_impl::torrent_map::const_iterator i = m_ses.m_torrents.begin()
 			, end(m_ses.m_torrents.end()); i != end; ++i)
@@ -2716,6 +2718,7 @@ namespace libtorrent
 		boost::shared_ptr<torrent> t = m_torrent.lock();
 		TORRENT_ASSERT(t);
 
+		TORRENT_ASSERT(!m_disconnecting);
 		TORRENT_ASSERT(t->valid_metadata());
 		TORRENT_ASSERT(block.piece_index >= 0);
 		TORRENT_ASSERT(block.piece_index < t->torrent_file().num_pieces());
@@ -2729,6 +2732,7 @@ namespace libtorrent
 			, block) == m_request_queue.end());
 
 		if (t->upload_mode()) return false;
+		if (m_disconnecting) return false;
 
 		piece_picker::piece_state_t state;
 		peer_speed_t speed = peer_speed();
@@ -3042,6 +3046,8 @@ namespace libtorrent
 		boost::shared_ptr<torrent> t = m_torrent.lock();
 		TORRENT_ASSERT(t);
 
+		if (m_disconnecting) return;
+
 		if ((int)m_download_queue.size() >= m_desired_queue_size
 			|| t->upload_mode()) return;
 
@@ -5066,7 +5072,15 @@ namespace libtorrent
 	}
 
 #ifdef TORRENT_DEBUG
-	struct peer_count_t { int num_peers; int num_peers_with_timeouts; int num_peers_with_nowant; };
+	struct peer_count_t
+	{
+		peer_count_t(): num_peers(0), num_peers_with_timeouts(0), num_peers_with_nowant(0), num_not_requested(0) {}
+		int num_peers;
+		int num_peers_with_timeouts;
+		int num_peers_with_nowant;
+		int num_not_requested;
+		std::vector<peer_connection const*> peers;
+	};
 
 	void peer_connection::check_invariant() const
 	{
@@ -5201,6 +5215,8 @@ namespace libtorrent
 					++num_requests[i->block].num_peers;
 					++num_requests[i->block].num_peers_with_timeouts;
 					++num_requests[i->block].num_peers_with_nowant;
+					++num_requests[i->block].num_not_requested;
+					num_requests[i->block].peers.push_back(&p);
 				}
 				for (std::vector<pending_block>::const_iterator i = p.download_queue().begin()
 					, end(p.download_queue().end()); i != end; ++i)
@@ -5208,15 +5224,17 @@ namespace libtorrent
 					if (!i->not_wanted && !i->timed_out) ++num_requests[i->block].num_peers;
 					if (i->timed_out) ++num_requests[i->block].num_peers_with_timeouts;
 					if (i->not_wanted) ++num_requests[i->block].num_peers_with_nowant;
+					num_requests[i->block].peers.push_back(&p);
 				}
 			}
 			for (std::map<piece_block, peer_count_t>::iterator i = num_requests.begin()
 				, end(num_requests.end()); i != end; ++i)
 			{
 				piece_block b = i->first;
-				int count = i->second.num_peers;
-				int count_with_timeouts = i->second.num_peers_with_timeouts;
-				int count_with_nowant = i->second.num_peers_with_nowant;
+				peer_count_t const& pc = i->second;
+				int count = pc.num_peers;
+				int count_with_timeouts = pc.num_peers_with_timeouts;
+				int count_with_nowant = pc.num_peers_with_nowant;
 				int picker_count = t->picker().num_peers(b);
 				if (!t->picker().is_downloaded(b))
 					TORRENT_ASSERT(picker_count == count);
diff --git a/src/policy.cpp b/src/policy.cpp
index 1d559a1cf..e74905ea9 100644
--- a/src/policy.cpp
+++ b/src/policy.cpp
@@ -129,6 +129,7 @@ namespace libtorrent
 		if (t.is_seed()) return;
 		if (c.no_download()) return;
 		if (t.upload_mode()) return;
+		if (c.is_disconnecting()) return;
 
 		// don't request pieces before we have the metadata
 		if (!t.valid_metadata()) return;