From 66520afdb8b4e3a86cf93836fc5e0b783113ef1c Mon Sep 17 00:00:00 2001
From: Joyee Cheung <joyeec9h3@gmail.com>
Date: Sat, 3 Feb 2018 17:30:48 +0800
Subject: [PATCH] util: skip type checks in internal getSystemErrorName

Backport-PR-URL: https://github.com/nodejs/node/pull/19191
PR-URL: https://github.com/nodejs/node/pull/18546
Reviewed-By: James M Snell <jasnell@gmail.com>
---
 lib/internal/util.js |  5 -----
 lib/util.js          | 10 +++++++++-
 2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/lib/internal/util.js b/lib/internal/util.js
index d915a699b54717..2d408bbbb68016 100644
--- a/lib/internal/util.js
+++ b/lib/internal/util.js
@@ -202,11 +202,6 @@ function getConstructorOf(obj) {
 }
 
 function getSystemErrorName(err) {
-  if (typeof err !== 'number' || err >= 0 || !Number.isSafeInteger(err)) {
-    throw new errors.TypeError('ERR_INVALID_ARG_TYPE', 'err',
-                               'negative number');
-  }
-
   const entry = errmap.get(err);
   return entry ? entry[0] : `Unknown system error ${err}`;
 }
diff --git a/lib/util.js b/lib/util.js
index 45f580d08f4d72..1379eb3f31a9d2 100644
--- a/lib/util.js
+++ b/lib/util.js
@@ -50,7 +50,7 @@ const {
   customInspectSymbol,
   deprecate,
   getConstructorOf,
-  getSystemErrorName,
+  getSystemErrorName: internalErrorName,
   isError,
   promisify,
   join
@@ -1065,6 +1065,14 @@ function callbackify(original) {
   return callbackified;
 }
 
+function getSystemErrorName(err) {
+  if (typeof err !== 'number' || err >= 0 || !Number.isSafeInteger(err)) {
+    throw new errors.TypeError('ERR_INVALID_ARG_TYPE', 'err',
+                               'negative number');
+  }
+  return internalErrorName(err);
+}
+
 // Keep the `exports =` so that various functions can still be monkeypatched
 module.exports = exports = {
   _errnoException,