end of connection more then once

When we close the pool connection it call the close of the connection and then call the callback. When we do it twice the callback not call.

The suggested solution is: At the connection end function we first check if already closed

end(callback) { if(this._closing){ return callback(); } this._closing = true; if (this.config.isServer) { const quitCmd = new EventEmitter(); setImmediate(() => { this.stream.end(); quitCmd.emit('end'); }); return quitCmd; } // trigger error if more commands enqueued after end command const quitCmd = this.addCommand(new Commands.Quit(callback)); this.addCommand = this._addCommandClosedState; return quitCmd; }

[sidorares]

@talGibly1 Agree, that should work. would you like to submit a PR?

[testn]

I think the right behavior should be that if you call end() more than once, the second time, it should fail.