Add "had_error" argument to the "onDisconnect" in node.tcp.Client

This is a boolean value which allows one to detect if the socket was closed
due to errors. There is not yet a way to look up the actual error code.

src/net.cc

@@ -422,6 +422,23 @@ Connection::OnReceive (const void *buf, size_t len)
     FatalException(try_catch);
 }
 
+void 
+Connection::OnDisconnect ()
+{
+  HandleScope scope;
+  Local<Value> callback_v = handle_->Get(ON_DISCONNECT_SYMBOL);
+  if (!callback_v->IsFunction()) return;
+  Handle<Function> callback = Handle<Function>::Cast(callback_v);
+
+  Handle<Value> argv[1];
+  argv[0] = socket_.errorno == 0 ? False() : True();
+
+  TryCatch try_catch;
+  callback->Call(handle_, 1, argv);
+  if (try_catch.HasCaught())
+    node::FatalException(try_catch);
+}
+
 #define DEFINE_SIMPLE_CALLBACK(name, symbol)                        \
 void name ()                                                        \
 {                                                                   \
@@ -437,7 +454,6 @@ void name ()                                                        \
 
 DEFINE_SIMPLE_CALLBACK(Connection::OnConnect, ON_CONNECT_SYMBOL)
 DEFINE_SIMPLE_CALLBACK(Connection::OnDrain, ON_DRAIN_SYMBOL)
-DEFINE_SIMPLE_CALLBACK(Connection::OnDisconnect, ON_DISCONNECT_SYMBOL)
 DEFINE_SIMPLE_CALLBACK(Connection::OnTimeout, ON_TIMEOUT_SYMBOL)
 DEFINE_SIMPLE_CALLBACK(Connection::OnEOF, ON_EOF_SYMBOL)
 

test/test-pingpong.js

@@ -26,7 +26,8 @@ function Ponger (socket) {
     socket.close();
   };
 
-  socket.onDisconnect = function () {
+  socket.onDisconnect = function (had_error) {
+    assertFalse(had_error);
     assertEquals("closed", socket.readyState);
     puts("ponger: onDisconnect");
     socket.server.close();

test/test-reconnecting-socket.js

@@ -3,7 +3,7 @@ var port = 8921;
 
 function onLoad () {
 
-  new node.tcp.Server(function (socket) {
+  var server = new node.tcp.Server(function (socket) {
     puts("new connection");
     socket.onConnect = function () {
       socket.send("hello\r\n");
@@ -13,10 +13,12 @@ function onLoad () {
       socket.close();
     };
 
-    socket.onDisconnect = function () {
-      socket.server.close();
+    socket.onDisconnect = function (had_error) {
+      //puts("server had_error: " + JSON.stringify(had_error));
+      assertFalse(had_error);
     };
-  }).listen(port);
+  });
+  server.listen(port);
 
   var count = 0;
   var client = new node.tcp.Connection();
@@ -32,10 +34,13 @@ function onLoad () {
     client.fullClose();
   };
 
-  client.onDisconnect = function () {
+  client.onDisconnect = function (had_error) {
+    assertFalse(had_error);
     puts("client disconnected");
-    if (count++ < 5)
-      client.connect(port);
+    if (count++ < 5) 
+      client.connect(port); // reconnect
+    else
+      server.close();
   };
 
   client.connect(port);

website/api.html

@@ -398,8 +398,13 @@ <h3 id="tcp_connection"><code>node.tcp.Connection</code></h3>
      You should probably just call <code>connection.close()</code> in this
      callback. 
 
-  <dt><code>conneciton.onDisconnect = function () { };</code></dt>
-  <dd>Called once the connection is fully disconnected.</dd>
+  <dt><code>conneciton.onDisconnect = function (had_error) { };</code></dt>
+  <dd>Called once the connection is fully disconnected.
+
+  <p>The callback is passed one boolean argument <code>had_error</code>.
+  This lets one know if the connect was closed due to an error. (TODO: look
+  up error codes.)
+  </dd>
 
   <dt><code>conneciton.onError = function () { };</code></dt>
   <dd>Called on an error.</dd>