http: unref socket timer on parser execute

When underlying `net.Socket` instance is consumed in http server - no
`data` events are emitted, and thus `socket.setTimeout` fires the
callback even if the data is constantly flowing into the socket.
Fix this by calling `socket._unrefTimer()` on every `onParserExecute`
call.
Fix: #5899
PR-URL: #6286
Reviewed-By: James M Snell <jasnell@gmail.com>

Author: indutny

lib/_http_server.js

@@ -364,6 +364,7 @@ function connectionListener(socket) {
 }
 
 functiononParserExecute(ret,d){
+socket._unrefTimer();
 debug('SERVER socketOnParserExecute %d',ret);
 onParserExecuteCommon(ret,undefined);
 }

test/parallel/test-http-server-consumed-timeout.js

@@ -0,0 +1,36 @@
+'use strict';
+
+constcommon=require('../common');
+constassert=require('assert');
+consthttp=require('http');
+
+constserver=http.createServer((req,res)=>{
+server.close();
+
+res.writeHead(200);
+res.flushHeaders();
+
+req.setTimeout(common.platformTimeout(200),()=>{
+assert(false,'Should not happen');
+});
+req.resume();
+req.once('end',common.mustCall(()=>{
+res.end();
+}));
+});
+
+server.listen(common.PORT,common.mustCall(()=>{
+constreq=http.request({
+port: common.PORT,
+method: 'POST'
+},(res)=>{
+constinterval=setInterval(()=>{
+req.write('a');
+},common.platformTimeout(25));
+setTimeout(()=>{
+clearInterval(interval);
+req.end();
+},common.platformTimeout(400));
+});
+req.write('.');
+}));