From 5583ed407aa6cb36e348b15ce300496bfe4d0c53 Mon Sep 17 00:00:00 2001
From: Arvid Norberg <arvid@libtorrent.org>
Date: Sat, 28 Apr 2012 05:05:39 +0000
Subject: [PATCH] fix some overflow and division by zero issues

---
 src/bandwidth_queue_entry.cpp |  5 ++++-
 src/peer_connection.cpp       | 10 ++++++++--
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/src/bandwidth_queue_entry.cpp b/src/bandwidth_queue_entry.cpp
index c13a564a9..6833b88d3 100644
--- a/src/bandwidth_queue_entry.cpp
+++ b/src/bandwidth_queue_entry.cpp
@@ -54,9 +54,13 @@ namespace libtorrent
 		TORRENT_ASSERT(assigned < request_size);
 		int quota = request_size - assigned;
 		TORRENT_ASSERT(quota >= 0);
+		--ttl;
+		if (quota == 0) return quota;
+
 		for (int j = 0; j < 5 && channel[j]; ++j)
 		{
 			if (channel[j]->throttle() == 0) continue;
+			if (channel[j]->tmp == 0) continue;
 			quota = (std::min)(int(boost::int64_t(channel[j]->distribute_quota)
 				* priority / channel[j]->tmp), quota);
 		}
@@ -64,7 +68,6 @@ namespace libtorrent
 		for (int j = 0; j < 5 && channel[j]; ++j)
 			channel[j]->use_quota(quota);
 		TORRENT_ASSERT(assigned <= request_size);
-		--ttl;
 		return quota;
 	}
 }
diff --git a/src/peer_connection.cpp b/src/peer_connection.cpp
index 169676044..133ada424 100644
--- a/src/peer_connection.cpp
+++ b/src/peer_connection.cpp
@@ -4702,7 +4702,13 @@ namespace libtorrent
 				// assume 20 kB/s
 				upload_capacity = (std::max)(20000, m_ses.m_peak_up_rate + 10000);
 			}
-			priority = (boost::uint64_t(m_est_reciprocation_rate) << 10) / upload_capacity;
+			int estimated_reciprocation_rate = m_est_reciprocation_rate;
+			// we cannot send faster than our upload rate anyway
+			if (estimated_reciprocation_rate < upload_capacity)
+				estimated_reciprocation_rate = upload_capacity;
+
+			priority = (boost::uint64_t(estimated_reciprocation_rate) << 14) / upload_capacity;
+			if (priority > 0xffff) priority = 0xffff;
 		}
 		else
 		{
@@ -4710,7 +4716,7 @@ namespace libtorrent
 			if (priority > 255) priority = 255;
 			priority += t->priority() << 8;
 		}
-		TORRENT_ASSERT(priority < 0xffff);
+		TORRENT_ASSERT(priority <= 0xffff);
 
 		// peers that we are not interested in are non-prioritized
 		TORRENT_ASSERT((m_channel_state[upload_channel] & peer_info::bw_limit) == 0);