Fix holding first closure for lifetime of connection

fixes #1785

Changes.md

@@ -4,6 +4,10 @@ This file is a manually maintained list of changes for each release. Feel free
 to add your changes here when sending pull requests. Also send corrections if
 you spot any mistakes.
 
+## HEAD
+
+* Fix holding first closure for lifetime of connection #1785
+
 ## v2.14.0 (2017-07-25)
 
 * Add new Amazon RDS ap-south-1 certificate CA to Amazon RDS SSL profile #1780

lib/protocol/Protocol.js

@@ -21,7 +21,7 @@ function Protocol(options) {
   this._callback                      = null;
   this._fatalError                    = null;
   this._quitSequence                  = null;
-  this._handshakeSequence             = null;
+  this._handshake                     = false;
   this._handshaked                    = false;
   this._ended                         = false;
   this._destroyed                     = false;
@@ -49,7 +49,11 @@ Protocol.prototype.handshake = function handshake(options, callback) {
   options = options || {};
   options.config = this._config;
 
-  return this._handshakeSequence = this._enqueue(new Sequences.Handshake(options, callback));
+  var sequence = this._enqueue(new Sequences.Handshake(options, callback));
+
+  this._handshake = true;
+
+  return sequence;
 };
 
 Protocol.prototype.query = function query(options, callback) {
@@ -202,7 +206,7 @@ Protocol.prototype._validateEnqueue = function _validateEnqueue(sequence) {
   } else if (this._destroyed) {
     err      = new Error(prefix + ' after being destroyed.');
     err.code = 'PROTOCOL_ENQUEUE_AFTER_DESTROY';
-  } else if (this._handshakeSequence && sequence.constructor === Sequences.Handshake) {
+  } else if ((this._handshake || this._handshaked) && sequence.constructor === Sequences.Handshake) {
     err      = new Error(prefix + ' after already enqueuing a Handshake.');
     err.code = 'PROTOCOL_ENQUEUE_HANDSHAKE_TWICE';
   } else {