From a1857ac619028fc6bf02e95ca0b80df85f379188 Mon Sep 17 00:00:00 2001
From: Oliver Salzburg <oliver.salzburg@gmail.com>
Date: Tue, 18 Oct 2016 18:48:44 +0200
Subject: [PATCH 1/2] doc: mention case-insensitive env on windows

On Windows OS, environment variables are case-insensitive and are treated
likewise in NodeJS. This can be confusing and can lead to hard-to-debug
problems when moving code from one environment to another.

Fixes: https://github.com/nodejs/node/issues/9157
---
 doc/api/process.md | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/doc/api/process.md b/doc/api/process.md
index dc311872fa8629..b39187dd47e616 100644
--- a/doc/api/process.md
+++ b/doc/api/process.md
@@ -708,6 +708,16 @@ console.log(process.env.TEST);
 // => undefined
 ```
 
+On Windows operating systems, environment variables are case-insensitive.
+
+Example:
+
+```js
+process.env.TEST = 1;
+console.log(process.env.test);
+// => 1
+```
+
 ## process.emitWarning(warning[, name][, ctor])
 <!-- YAML
 added: v6.0.0

From b707743d346c20d20b005c945a2f2e28c1e463b6 Mon Sep 17 00:00:00 2001
From: Oliver Salzburg <oliver.salzburg@gmail.com>
Date: Tue, 18 Oct 2016 22:02:19 +0200
Subject: [PATCH 2/2] test: case sensitivity of env variables

Environment variables should be treated case-insensitive on Windows
platforms and case-sensitive on UNIX platforms
---
 test/parallel/test-process-env.js | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/test/parallel/test-process-env.js b/test/parallel/test-process-env.js
index d3b1682629a537..21898d19425ca3 100644
--- a/test/parallel/test-process-env.js
+++ b/test/parallel/test-process-env.js
@@ -1,6 +1,6 @@
 'use strict';
 
-require('../common');
+const common = require('../common');
 const assert = require('assert');
 
 // changes in environment should be visible to child processes
@@ -67,3 +67,17 @@ assert.equal(3, date.getUTCHours());
 assert.equal(5, date.getHours());
 */
 /* eslint-enable max-len */
+
+// Environment variables should be case-insensitive on Windows, and
+// case-sensitive on other platforms.
+process.env.TEST = 'test';
+assert.strictEqual(process.env.TEST, 'test');
+// Check both mixed case and lower case, to avoid any regressions that might
+// simply convert input to lower case.
+if (common.isWindows) {
+  assert.strictEqual(process.env.test, 'test');
+  assert.strictEqual(process.env.teST, 'test');
+} else {
+  assert.strictEqual(process.env.test, undefined);
+  assert.strictEqual(process.env.teST, undefined);
+}