http: cleanup ClientRequest oncreate

PR-URL: #36862
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Daniele Belardi <dwon.dnl@gmail.com>

Author: ronag

lib/_http_client.js

@@ -44,6 +44,7 @@ const {
 constnet=require('net');
 consturl=require('url');
 constassert=require('internal/assert');
+const{ once }=require('internal/util');
 const{
 _checkIsHttpToken: checkIsHttpToken,
  debug,
@@ -240,8 +241,6 @@ function ClientRequest(input, options, cb) {
 this.host=host;
 this.protocol=protocol;
 
-letcalled=false;
-
 if(this.agent){
 // If there is an agent we should default to Connection:keep-alive,
 // but only if the Agent will actually reuse the connection!
@@ -305,18 +304,6 @@ function ClientRequest(input, options, cb) {
 options.headers);
 }
 
-constoncreate=(err,socket)=>{
-if(called)
-return;
-called=true;
-if(err){
-process.nextTick(()=>this.emit('error',err));
-return;
-}
-this.onSocket(socket);
-this._deferToConnect(null,null,()=>this._flush());
-};
-
 // initiate connection
 if(this.agent){
 this.agent.addRequest(this,options);
@@ -325,20 +312,27 @@ function ClientRequest(input, options, cb) {
 this._last=true;
 this.shouldKeepAlive=false;
 if(typeofoptions.createConnection==='function'){
-constnewSocket=options.createConnection(options,oncreate);
-if(newSocket&&!called){
-called=true;
-this.onSocket(newSocket);
-}else{
-return;
+constoncreate=once((err,socket)=>{
+if(err){
+process.nextTick(()=>this.emit('error',err));
+}else{
+this.onSocket(socket);
+}
+});
+
+try{
+constnewSocket=options.createConnection(options,oncreate);
+if(newSocket){
+oncreate(null,newSocket);
+}
+}catch(err){
+oncreate(err);
 }
 }else{
 debug('CLIENT use net.createConnection',options);
 this.onSocket(net.createConnection(options));
 }
 }
-
-this._deferToConnect(null,null,()=>this._flush());
 }
 ObjectSetPrototypeOf(ClientRequest.prototype,OutgoingMessage.prototype);
 ObjectSetPrototypeOf(ClientRequest,OutgoingMessage);
@@ -843,6 +837,7 @@ function onSocketNT(req, socket, err) {
 _destroy(req,null,err);
 }else{
 tickOnSocket(req,socket);
+req._flush();
 }
 }