test: ensure _handle property existence

`test-stdtout-close-unref.js` will fail if `process.stdin._handle` does not exist. On UNIX-like operating systems, you can see this failure this way: ./node test/parallel/test-stdout-close-unref.js < /dev/null This issue has been experienced by @bengl and @drewfish in a Docker container. I'm not sure why they are experiencing it in their environment, but since it is possible that the `_handle` property does not exist, let's use `child_process.spawn()` to make sure it exists. PR-URL: #5916 Reviewed-By: Jeremiah Senkpiel <[email protected]>

Author: Trott

test/parallel/test-stdout-close-unref.js

@@ -1,16 +1,30 @@
 'use strict';
-require('../common');
-varassert=require('assert');
+constcommon=require('../common');
+constassert=require('assert');
+constspawn=require('child_process').spawn;
 
-varerrs=0;
+if(process.argv[2]==='child'){
+varerrs=0;
 
-process.stdin.resume();
-process.stdin._handle.close();
-process.stdin._handle.unref();// Should not segfault.
-process.stdin.on('error',function(err){
-errs++;
-});
+process.stdin.resume();
+process.stdin._handle.close();
+process.stdin._handle.unref();// Should not segfault.
+process.stdin.on('error',function(err){
+errs++;
+});
 
-process.on('exit',function(){
-assert.strictEqual(errs,1);
-});
+process.on('exit',function(){
+assert.strictEqual(errs,1);
+});
+return;
+}
+
+// Use spawn so that we can be sure that stdin has a _handle property.
+// Refs: https://github.com/nodejs/node/pull/5916
+constproc=spawn(process.execPath,[__filename,'child'],{stdio: 'pipe'});
+
+proc.stderr.pipe(process.stderr);
+proc.on('exit',common.mustCall(function(exitCode){
+if(exitCode!==0)
+process.exitCode=exitCode;
+}));