Extend Pool methods to enable create conns even if there are free ones available

lib/Pool.js

@@ -28,14 +28,27 @@ Pool.prototype.getConnection = function (cb) {
   }
 
   var connection;
-  var pool = this;
 
   if (this._freeConnections.length > 0) {
     connection = this._freeConnections.shift();
-
     return this.acquireConnection(connection, cb);
   }
 
+  return this.createConnection(cb);
+
+};
+
+Pool.prototype.createConnection = function (cb) {
+
+  if (this._closed) {
+    return process.nextTick(function(){
+      return cb(new Error('Pool is closed.'));
+    });
+  }
+
+  var connection;
+  var pool = this;
+
   if (this.config.connectionLimit === 0 || this._allConnections.length < this.config.connectionLimit) {
     connection = new PoolConnection(this, { config: this.config.newConnectionConfig() });
 

test/unit/pool/test-connection-create.js

@@ -0,0 +1,25 @@
+var assert = require('assert');
+var common = require('../../common');
+var Connection = common.Connection;
+var EventEmitter = require('events').EventEmitter;
+var pool = common.createPool({
+  port: common.fakeServerPort
+});
+var PoolConnection = common.PoolConnection;
+
+var server = common.createFakeServer();
+
+server.listen(common.fakeServerPort, function(err) {
+  assert.ifError(err);
+
+  pool.createConnection(function(err, connection) {
+    assert.ifError(err);
+
+    assert(connection instanceof PoolConnection);
+    assert(connection instanceof Connection);
+    assert(connection instanceof EventEmitter);
+
+    connection.destroy();
+    server.destroy();
+  });
+});