lib,src: make constants not inherit from Object

Make sure `constants` object and all the nested objects don't inherit
from `Object.prototype` but from `null`.

PR-URL: https://github.com/nodejs/node/pull/10458
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Brian White <mscdex@mscdex.net>

2 files changed, 3 insertions, 4 deletions

diff --git a/lib/fs.js b/lib/fs.js
index 8c92db957b..3d65b2efa0 100644
--- a/lib/fs.js
+++ b/lib/fs.js
@@ -1058,7 +1058,7 @@ fs.fchmodSync = function(fd, mode) {
   return binding.fchmod(fd, modeNum(mode));
 };
 
-if (constants.hasOwnProperty('O_SYMLINK')) {
+if (constants.O_SYMLINK !== undefined) {
   fs.lchmod = function(path, mode, callback) {
     callback = maybeCallback(callback);
     fs.open(path, constants.O_WRONLY | constants.O_SYMLINK, function(err, fd) {
@@ -1116,7 +1116,7 @@ fs.chmodSync = function(path, mode) {
   return binding.chmod(pathModule._makeLong(path), modeNum(mode));
 };
 
-if (constants.hasOwnProperty('O_SYMLINK')) {
+if (constants.O_SYMLINK !== undefined) {
   fs.lchown = function(path, uid, gid, callback) {
     callback = maybeCallback(callback);
     fs.open(path, constants.O_WRONLY | constants.O_SYMLINK, function(err, fd) {
diff --git a/lib/internal/process.js b/lib/internal/process.js
index a53618fd37..b4fe19093a 100644
--- a/lib/internal/process.js
+++ b/lib/internal/process.js
@@ -201,8 +201,7 @@ function setupSignalHandlers() {
   const signalWraps = {};
 
   function isSignal(event) {
-    return typeof event === 'string' &&
-           lazyConstants().hasOwnProperty(event);
+    return typeof event === 'string' && lazyConstants()[event] !== undefined;
   }
 
   // Detect presence of a listener for the special signal types