diff --git a/Jamfile b/Jamfile
index f9b68dce6..869c99592 100755
--- a/Jamfile
+++ b/Jamfile
@@ -83,7 +83,7 @@ rule linking ( properties * )
 	{
 		# for backtraces in assertion failures
 		# which only works on ELF targets with gcc
-		result += <cxxflags>-rdynamic <source>src/assert.cpp ;
+		result += <linkflags>-export-dynamic <cxxflags>-rdynamic ;
 	}
 
 	if <boost>source in $(properties)
@@ -104,6 +104,15 @@ rule building ( properties * )
 {
 	local result ;
 
+	if <toolset>gcc in $(properties)
+		&& <target-os>linux in $(properties)
+		&& <variant>debug in $(properties)
+	{
+		# for backtraces in assertion failures
+		# which only works on ELF targets with gcc
+		result += <source>src/assert.cpp ;
+	}
+
 	if <openssl>off in $(properties)
 	{
 		result += <source>src/sha1.cpp ;
@@ -270,6 +279,11 @@ local usage-requirements =
 # disable bogus deprecation warnings on msvc8
 	<toolset>msvc:<define>_SCL_SECURE_NO_DEPRECATE
 	<toolset>msvc:<define>_CRT_SECURE_NO_DEPRECATE
+# msvc optimizations
+	<toolset>msvc,<variant>release:<linkflags>/OPT:ICF=5
+	<toolset>msvc,<variant>release:<linkflags>/OPT:REF
+# disable warning C4503: decorated name length exceeded, name was truncated
+	<toolset>msvc:<cxxflags>/wd4503
 	;
 
 project torrent ;
diff --git a/include/libtorrent/alert.hpp b/include/libtorrent/alert.hpp
index b6b6711dc..954e39ef5 100755
--- a/include/libtorrent/alert.hpp
+++ b/include/libtorrent/alert.hpp
@@ -36,7 +36,6 @@ POSSIBILITY OF SUCH DAMAGE.
 #include <memory>
 #include <queue>
 #include <string>
-#include <cassert>
 #include <typeinfo>
 
 #ifdef _MSC_VER
@@ -56,6 +55,7 @@ POSSIBILITY OF SUCH DAMAGE.
 
 #include "libtorrent/time.hpp"
 #include "libtorrent/config.hpp"
+#include "libtorrent/assert.hpp"
 
 #ifndef TORRENT_MAX_ALERT_TYPES
 #define TORRENT_MAX_ALERT_TYPES 15
diff --git a/include/libtorrent/assert.hpp b/include/libtorrent/assert.hpp
index 488afe778..8ab605080 100644
--- a/include/libtorrent/assert.hpp
+++ b/include/libtorrent/assert.hpp
@@ -33,15 +33,17 @@ POSSIBILITY OF SUCH DAMAGE.
 #ifndef TORRENT_ASSERT_HPP_INCLUDED
 #define TORRENT_ASSERT_HPP_INCLUDED
 
+#include <cassert>
+
 #ifndef NDEBUG
-#if defined __linux__ && defined _GNUC
+#if defined __linux__ && defined __GNUC__
 #ifdef assert
 #undef assert
 #endif
 
-void assert_fail(int line, char const* file);
+void assert_fail(const char* expr, int line, char const* file, char const* function);
 
-#define assert(x) if (!(x)) assert_fail(__LINE__, __FILE__)
+#define assert(x) if (!(x)) assert_fail(#x, __LINE__, __FILE__, __PRETTY_FUNCTION__)
 
 #endif
 
diff --git a/include/libtorrent/config.hpp b/include/libtorrent/config.hpp
index b36d4da22..1281ab84c 100755
--- a/include/libtorrent/config.hpp
+++ b/include/libtorrent/config.hpp
@@ -34,6 +34,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #define TORRENT_CONFIG_HPP_INCLUDED
 
 #include <boost/config.hpp>
+#include "libtorrent/assert.hpp"
 
 #if defined(__GNUC__) && __GNUC__ >= 4
 
diff --git a/include/libtorrent/entry.hpp b/include/libtorrent/entry.hpp
index 59e29803d..7fd6c8c53 100755
--- a/include/libtorrent/entry.hpp
+++ b/include/libtorrent/entry.hpp
@@ -64,10 +64,10 @@ POSSIBILITY OF SUCH DAMAGE.
 #include <list>
 #include <string>
 #include <stdexcept>
-#include <cassert>
 
 #include "libtorrent/size_type.hpp"
 #include "libtorrent/config.hpp"
+#include "libtorrent/assert.hpp"
 
 namespace libtorrent
 {
diff --git a/include/libtorrent/hasher.hpp b/include/libtorrent/hasher.hpp
index 932f2b100..71b7f9ede 100755
--- a/include/libtorrent/hasher.hpp
+++ b/include/libtorrent/hasher.hpp
@@ -33,11 +33,11 @@ POSSIBILITY OF SUCH DAMAGE.
 #ifndef TORRENT_HASHER_HPP_INCLUDED
 #define TORRENT_HASHER_HPP_INCLUDED
 
-#include <cassert>
 #include <boost/cstdint.hpp>
 
 #include "libtorrent/peer_id.hpp"
 #include "libtorrent/config.hpp"
+#include "libtorrent/assert.hpp"
 #include "zlib.h"
 
 #ifdef TORRENT_USE_OPENSSL
diff --git a/include/libtorrent/intrusive_ptr_base.hpp b/include/libtorrent/intrusive_ptr_base.hpp
index 39ba2e77f..ed6944ebb 100644
--- a/include/libtorrent/intrusive_ptr_base.hpp
+++ b/include/libtorrent/intrusive_ptr_base.hpp
@@ -34,8 +34,8 @@ POSSIBILITY OF SUCH DAMAGE.
 #define TORRENT_INTRUSIVE_PTR_BASE
 
 #include <boost/detail/atomic_count.hpp>
-#include <cassert>
 #include "libtorrent/config.hpp"
+#include "libtorrent/assert.hpp"
 
 namespace libtorrent
 {
diff --git a/include/libtorrent/invariant_check.hpp b/include/libtorrent/invariant_check.hpp
index c6eacf338..3eaacf34c 100755
--- a/include/libtorrent/invariant_check.hpp
+++ b/include/libtorrent/invariant_check.hpp
@@ -5,7 +5,7 @@
 #ifndef TORRENT_INVARIANT_ACCESS_HPP_INCLUDED
 #define TORRENT_INVARIANT_ACCESS_HPP_INCLUDED
 
-#include <cassert>
+#include "libtorrent/assert.hpp"
 
 namespace libtorrent
 {
diff --git a/include/libtorrent/kademlia/node.hpp b/include/libtorrent/kademlia/node.hpp
index 850333043..ee75e7f0a 100644
--- a/include/libtorrent/kademlia/node.hpp
+++ b/include/libtorrent/kademlia/node.hpp
@@ -34,7 +34,6 @@ POSSIBILITY OF SUCH DAMAGE.
 #define NODE_HPP
 
 #include <algorithm>
-#include <cassert>
 #include <map>
 #include <set>
 
@@ -45,6 +44,7 @@ POSSIBILITY OF SUCH DAMAGE.
 
 #include <libtorrent/io.hpp>
 #include <libtorrent/session_settings.hpp>
+#include <libtorrent/assert.hpp>
 
 #include <boost/cstdint.hpp>
 #include <boost/optional.hpp>
diff --git a/include/libtorrent/kademlia/node_id.hpp b/include/libtorrent/kademlia/node_id.hpp
index eb4d6c539..5e732acac 100644
--- a/include/libtorrent/kademlia/node_id.hpp
+++ b/include/libtorrent/kademlia/node_id.hpp
@@ -33,10 +33,10 @@ POSSIBILITY OF SUCH DAMAGE.
 #define NODE_ID_HPP
 
 #include <algorithm>
-#include <cassert>
 
 #include <boost/cstdint.hpp>
 #include "libtorrent/peer_id.hpp"
+#include "libtorrent/assert.hpp"
 
 namespace libtorrent { namespace dht
 {
diff --git a/include/libtorrent/pe_crypto.hpp b/include/libtorrent/pe_crypto.hpp
index 91616c42d..e2276dee6 100644
--- a/include/libtorrent/pe_crypto.hpp
+++ b/include/libtorrent/pe_crypto.hpp
@@ -35,13 +35,12 @@ POSSIBILITY OF SUCH DAMAGE.
 #ifndef TORRENT_PE_CRYPTO_HPP_INCLUDED
 #define TORRENT_PE_CRYPTO_HPP_INCLUDED
 
-#include <cassert>
-
 #include <openssl/dh.h>
 #include <openssl/engine.h>
 #include <openssl/rc4.h>
 
-#include "peer_id.hpp" // For sha1_hash
+#include "libtorrent/peer_id.hpp" // For sha1_hash
+#include "libtorrent/assert.hpp"
 
 namespace libtorrent
 {
diff --git a/include/libtorrent/peer_id.hpp b/include/libtorrent/peer_id.hpp
index b66c1d4bc..57303e2fd 100755
--- a/include/libtorrent/peer_id.hpp
+++ b/include/libtorrent/peer_id.hpp
@@ -35,12 +35,12 @@ POSSIBILITY OF SUCH DAMAGE.
 
 #include <iostream>
 #include <iomanip>
-#include <cassert>
 #include <cctype>
 #include <algorithm>
 #include <string>
 
 #include "libtorrent/config.hpp"
+#include "libtorrent/assert.hpp"
 
 namespace libtorrent
 {
diff --git a/include/libtorrent/piece_picker.hpp b/include/libtorrent/piece_picker.hpp
index 8e396bdff..4305c2dde 100755
--- a/include/libtorrent/piece_picker.hpp
+++ b/include/libtorrent/piece_picker.hpp
@@ -35,7 +35,6 @@ POSSIBILITY OF SUCH DAMAGE.
 #include <algorithm>
 #include <vector>
 #include <bitset>
-#include <cassert>
 #include <utility>
 
 #ifdef _MSC_VER
@@ -52,6 +51,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "libtorrent/socket.hpp"
 #include "libtorrent/session_settings.hpp"
 #include "libtorrent/config.hpp"
+#include "libtorrent/assert.hpp"
 
 namespace libtorrent
 {
diff --git a/src/assert.cpp b/src/assert.cpp
index c2cb1b4a5..da79a745b 100644
--- a/src/assert.cpp
+++ b/src/assert.cpp
@@ -32,9 +32,11 @@ POSSIBILITY OF SUCH DAMAGE.
 
 #ifndef NDEBUG
 
+#include <stdlib.h>
+#include <stdio.h>
 #include <execinfo.h>
 
-void assert_fail(int line, char const* file)
+void assert_fail(char const* expr, int line, char const* file, char const* function)
 {
 
 	fprintf(stderr, "assertion failed. Please file a bugreport at "
@@ -42,9 +44,11 @@ void assert_fail(int line, char const* file)
 		"Please include the following information:\n\n"
 		"file: '%s'\n"
 		"line: %d\n"
-		"stack:\n", file, line);
+		"function: %s\n"
+		"expression: %s\n"
+		"stack:\n", file, line, function, expr);
 
-	void* stacktrace[50];
+	void* stack[50];
 	int size = backtrace(stack, 50);
 	char** symbols = backtrace_symbols(stack, size);
 
@@ -54,6 +58,7 @@ void assert_fail(int line, char const* file)
 	}
 
 	free(symbols);
+	exit(1);
 }
 
 #endif
diff --git a/src/escape_string.cpp b/src/escape_string.cpp
index 02a4fa085..673d56288 100755
--- a/src/escape_string.cpp
+++ b/src/escape_string.cpp
@@ -31,9 +31,9 @@ POSSIBILITY OF SUCH DAMAGE.
 */
 
 #include "libtorrent/pch.hpp"
+#include "libtorrent/assert.hpp"
 
 #include <string>
-#include <cassert>
 #include <stdexcept>
 #include <sstream>
 #include <iomanip>
diff --git a/src/kademlia/node_id.cpp b/src/kademlia/node_id.cpp
index 4ed413714..ad06c515d 100644
--- a/src/kademlia/node_id.cpp
+++ b/src/kademlia/node_id.cpp
@@ -34,10 +34,10 @@ POSSIBILITY OF SUCH DAMAGE.
 
 #include <algorithm>
 #include <iomanip>
-#include <cassert>
 #include <boost/bind.hpp>
 
 #include "libtorrent/kademlia/node_id.hpp"
+#include "libtorrent/assert.hpp"
 
 using boost::bind;
 
diff --git a/src/pe_crypto.cpp b/src/pe_crypto.cpp
index 437c93e2c..981eca63d 100644
--- a/src/pe_crypto.cpp
+++ b/src/pe_crypto.cpp
@@ -32,13 +32,13 @@ POSSIBILITY OF SUCH DAMAGE.
 
 #ifndef TORRENT_DISABLE_ENCRYPTION
 
-#include <cassert>
 #include <algorithm>
 
 #include <openssl/dh.h>
 #include <openssl/engine.h>
 
 #include "libtorrent/pe_crypto.hpp"
+#include "libtorrent/assert.hpp"
 
 namespace libtorrent {
 
diff --git a/src/peer_connection.cpp b/src/peer_connection.cpp
index c6be880ad..c7bd3dc5e 100755
--- a/src/peer_connection.cpp
+++ b/src/peer_connection.cpp
@@ -51,6 +51,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "libtorrent/aux_/session_impl.hpp"
 #include "libtorrent/policy.hpp"
 #include "libtorrent/socket_type.hpp"
+#include "libtorrent/assert.hpp"
 
 using boost::bind;
 using boost::shared_ptr;
diff --git a/src/upnp.cpp b/src/upnp.cpp
index aefff41b1..e16c136bb 100644
--- a/src/upnp.cpp
+++ b/src/upnp.cpp
@@ -323,7 +323,13 @@ try
 #endif
 {
 	using namespace libtorrent::detail;
-	if (e) return;
+	if (e)
+	{
+#ifdef TORRENT_UPNP_LOGGING
+		m_log << time_now_string() << " *** on_reply aborted: " << e.message() << std::endl;
+#endif
+		return;
+	}
 
 	// parse out the url for the device
 
@@ -843,9 +849,16 @@ void upnp::on_upnp_map_response(asio::error_code const& e
 	{
 #ifdef TORRENT_UPNP_LOGGING
 		m_log << time_now_string()
-			<< " <== error while adding portmap: " << p.message() << std::endl;
+			<< " <== error while adding portmap: " << p.status_code() << " " << p.message() << std::endl;
 #endif
-		m_devices.erase(d);
+		for (int i = 0; i < num_mappings; ++i)
+		{
+			if (d.mapping[i].need_update)
+			{
+				map_port(d, i);
+				return;
+			}
+		}
 		return;
 	}