net: emit close on unconnected socket

Socket should always emit 'close'. Regardless
whether it has been connected or not.

Author: ronag

lib/net.js

@@ -660,10 +660,12 @@ Socket.prototype._destroy = function(exception, cb) {
     this._handle.onread = noop;
     this._handle = null;
     this._sockname = null;
+    cb(exception);
+  } else {
+    cb(exception);
+    process.nextTick(emitCloseNT, this);
   }
 
-  cb(exception);
-
   if (this._server) {
     debug('has server');
     this._server._connections--;

test/parallel/test-net-connect-destroy.js

@@ -0,0 +1,7 @@
+'use strict';
+const common = require('../common');
+const net = require('net');
+
+const socket = new net.Socket()
+socket.on('close', common.mustCall());
+socket.destroy();