From a57cb2a7a6721ed25fa7cfaa577ae1a985fc31f7 Mon Sep 17 00:00:00 2001
From: Christopher Kohlhoff <chris@kohlhoff.com>
Date: Sat, 2 Dec 2017 18:25:44 +1100
Subject: [PATCH] Suppress recv truncation errors on Windows, to match POSIX
 behaviour.

---
 example/cpp03/fork/daemon.cpp                 |  2 +-
 example/cpp03/tutorial/daytime5/server.cpp    |  6 +-----
 example/cpp03/tutorial/daytime6/server.cpp    |  2 +-
 example/cpp03/tutorial/daytime7/server.cpp    |  2 +-
 example/cpp11/fork/daemon.cpp                 |  2 +-
 include/boost/asio/detail/impl/socket_ops.ipp | 16 ++++++++++++++++
 6 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/example/cpp03/fork/daemon.cpp b/example/cpp03/fork/daemon.cpp
index 494e8d1b..53fdf287 100644
--- a/example/cpp03/fork/daemon.cpp
+++ b/example/cpp03/fork/daemon.cpp
@@ -39,7 +39,7 @@ private:
 
   void handle_receive(const boost::system::error_code& ec)
   {
-    if (!ec || ec == boost::asio::error::message_size)
+    if (!ec)
     {
       using namespace std; // For time_t, time and ctime;
       time_t now = time(0);
diff --git a/example/cpp03/tutorial/daytime5/server.cpp b/example/cpp03/tutorial/daytime5/server.cpp
index 72995878..6dc7816a 100644
--- a/example/cpp03/tutorial/daytime5/server.cpp
+++ b/example/cpp03/tutorial/daytime5/server.cpp
@@ -36,11 +36,7 @@ int main()
       boost::array<char, 1> recv_buf;
       udp::endpoint remote_endpoint;
       boost::system::error_code error;
-      socket.receive_from(boost::asio::buffer(recv_buf),
-          remote_endpoint, 0, error);
-
-      if (error && error != boost::asio::error::message_size)
-        throw boost::system::system_error(error);
+      socket.receive_from(boost::asio::buffer(recv_buf), remote_endpoint);
 
       std::string message = make_daytime_string();
 
diff --git a/example/cpp03/tutorial/daytime6/server.cpp b/example/cpp03/tutorial/daytime6/server.cpp
index 09f9c050..9a64ac1e 100644
--- a/example/cpp03/tutorial/daytime6/server.cpp
+++ b/example/cpp03/tutorial/daytime6/server.cpp
@@ -47,7 +47,7 @@ private:
   void handle_receive(const boost::system::error_code& error,
       std::size_t /*bytes_transferred*/)
   {
-    if (!error || error == boost::asio::error::message_size)
+    if (!error)
     {
       boost::shared_ptr<std::string> message(
           new std::string(make_daytime_string()));
diff --git a/example/cpp03/tutorial/daytime7/server.cpp b/example/cpp03/tutorial/daytime7/server.cpp
index c83e74e4..ee00e816 100644
--- a/example/cpp03/tutorial/daytime7/server.cpp
+++ b/example/cpp03/tutorial/daytime7/server.cpp
@@ -119,7 +119,7 @@ private:
 
   void handle_receive(const boost::system::error_code& error)
   {
-    if (!error || error == boost::asio::error::message_size)
+    if (!error)
     {
       boost::shared_ptr<std::string> message(
           new std::string(make_daytime_string()));
diff --git a/example/cpp11/fork/daemon.cpp b/example/cpp11/fork/daemon.cpp
index 4cbdd16a..4e055736 100644
--- a/example/cpp11/fork/daemon.cpp
+++ b/example/cpp11/fork/daemon.cpp
@@ -35,7 +35,7 @@ private:
         boost::asio::buffer(recv_buffer_), remote_endpoint_,
         [this](boost::system::error_code ec, std::size_t /*n*/)
         {
-          if (!ec || ec == boost::asio::error::message_size)
+          if (!ec)
           {
             using namespace std; // For time_t, time and ctime;
             time_t now = time(0);
diff --git a/include/boost/asio/detail/impl/socket_ops.ipp b/include/boost/asio/detail/impl/socket_ops.ipp
index 2b97387a..94be0f28 100644
--- a/include/boost/asio/detail/impl/socket_ops.ipp
+++ b/include/boost/asio/detail/impl/socket_ops.ipp
@@ -771,6 +771,8 @@ signed_size_type recv(socket_type s, buf* bufs, size_t count,
     ec = boost::asio::error::connection_reset;
   else if (ec.value() == ERROR_PORT_UNREACHABLE)
     ec = boost::asio::error::connection_refused;
+  else if (ec.value() == WSAEMSGSIZE || ec.value() == ERROR_MORE_DATA)
+    ec.assign(0, ec.category());
   if (result != 0)
     return socket_error_retval;
   ec = boost::system::error_code();
@@ -849,6 +851,10 @@ void complete_iocp_recv(state_type state,
   {
     ec = boost::asio::error::connection_refused;
   }
+  else if (ec.value() == WSAEMSGSIZE || ec.value() == ERROR_MORE_DATA)
+  {
+    ec.assign(0, ec.category());
+  }
 
   // Check for connection closed.
   else if (!ec && bytes_transferred == 0
@@ -919,6 +925,8 @@ signed_size_type recvfrom(socket_type s, buf* bufs, size_t count,
     ec = boost::asio::error::connection_reset;
   else if (ec.value() == ERROR_PORT_UNREACHABLE)
     ec = boost::asio::error::connection_refused;
+  else if (ec.value() == WSAEMSGSIZE || ec.value() == ERROR_MORE_DATA)
+    ec.assign(0, ec.category());
   if (result != 0)
     return socket_error_retval;
   ec = boost::system::error_code();
@@ -988,6 +996,10 @@ void complete_iocp_recvfrom(
   {
     ec = boost::asio::error::connection_refused;
   }
+  else if (ec.value() == WSAEMSGSIZE || ec.value() == ERROR_MORE_DATA)
+  {
+    ec.assign(0, ec.category());
+  }
 }
 
 #else // defined(BOOST_ASIO_HAS_IOCP)
@@ -1101,6 +1113,10 @@ void complete_iocp_recvmsg(
   {
     ec = boost::asio::error::connection_refused;
   }
+  else if (ec.value() == WSAEMSGSIZE || ec.value() == ERROR_MORE_DATA)
+  {
+    ec.assign(0, ec.category());
+  }
 }
 
 #else // defined(BOOST_ASIO_HAS_IOCP)