From 205d70da3c9f588b67428463a1a6e1ea16f14fb3 Mon Sep 17 00:00:00 2001
From: Arvid Norberg <arvid@libtorrent.org>
Date: Sun, 25 Nov 2012 07:03:37 +0000
Subject: [PATCH] merged uTP fix from RC_0_16

---
 include/libtorrent/packet_buffer.hpp |  2 +-
 src/packet_buffer.cpp                |  2 +-
 test/test_primitives.cpp             | 19 +++++++++++++++++++
 3 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/include/libtorrent/packet_buffer.hpp b/include/libtorrent/packet_buffer.hpp
index 0e46fe3cf..759ee27d9 100644
--- a/include/libtorrent/packet_buffer.hpp
+++ b/include/libtorrent/packet_buffer.hpp
@@ -107,7 +107,7 @@ namespace libtorrent
 		std::size_t m_size;
 
 		// This defines the first index that is part of the m_storage.
-		// The last index is (m_first + (m_capacity - 1)) & 0xffff.
+		// last is one passed the last used slot
 		index_type m_first;
 		index_type m_last;
 	};
diff --git a/src/packet_buffer.cpp b/src/packet_buffer.cpp
index 68e2d2d8d..da8eea280 100644
--- a/src/packet_buffer.cpp
+++ b/src/packet_buffer.cpp
@@ -106,7 +106,7 @@ namespace libtorrent {
 				// We have wrapped.
 				if (idx >= ((m_first + m_capacity) & 0xffff) && m_capacity < 0xffff)
 				{
-					reserve(m_capacity + (idx - ((m_first + m_capacity) & 0xffff)));
+					reserve(m_capacity + (idx + 1 - ((m_first + m_capacity) & 0xffff)));
 				}
 			}
 			if (compare_less_wrap(m_last, (idx + 1) & 0xffff, 0xffff))
diff --git a/test/test_primitives.cpp b/test/test_primitives.cpp
index 407cf0ce6..52a3bccef 100644
--- a/test/test_primitives.cpp
+++ b/test/test_primitives.cpp
@@ -705,6 +705,25 @@ int test_main()
 		TEST_CHECK(pb.at(2) == (void*)2);
 	}
 
+	{
+		// test wrapping the indices
+		packet_buffer pb;
+
+		TEST_EQUAL(pb.size(), 0);
+
+		pb.insert(0xfff3, (void*)1);
+		TEST_CHECK(pb.at(0xfff3) == (void*)1);
+
+		int new_index = (0xfff3 + pb.capacity()) & 0xffff;
+		pb.insert(new_index, (void*)2);
+		TEST_CHECK(pb.at(new_index) == (void*)2);
+
+		void* old = pb.remove(0xfff3);
+		TEST_CHECK(old == (void*)1);
+		TEST_CHECK(pb.at(0xfff3) == (void*)0);
+		TEST_CHECK(pb.at(new_index) == (void*)2);
+	}
+
 	TEST_CHECK(error_code(errors::http_error).message() == "HTTP error");
 	TEST_CHECK(error_code(errors::missing_file_sizes).message() == "missing or invalid 'file sizes' entry");
 	TEST_CHECK(error_code(errors::unsupported_protocol_version).message() == "unsupported protocol version");