From 63f10b9f0da0539b499a076f2951526ecae8260a Mon Sep 17 00:00:00 2001
From: Ruben Bridgewater <ruben@bridgewater.de>
Date: Mon, 20 Jan 2020 21:37:14 +0100
Subject: [PATCH] tty: do not end in an infinite warning recursion

It was possible that this warning ends up in an infinite recursion.
The reason is that printing the warning triggered a color check and
that triggered another warning. Limiting it to a single warning
prevents this.

PR-URL: https://github.com/nodejs/node/pull/31429
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
---
 lib/internal/tty.js                              | 16 ++++++++++++----
 .../test-tty-color-support-warning-2.js          |  8 ++++++++
 .../test-tty-color-support-warning-2.out         |  2 ++
 .../pseudo-tty/test-tty-color-support-warning.js |  9 +++++++++
 .../test-tty-color-support-warning.out           |  2 ++
 test/pseudo-tty/test-tty-color-support.out       |  7 -------
 6 files changed, 33 insertions(+), 11 deletions(-)
 create mode 100644 test/pseudo-tty/test-tty-color-support-warning-2.js
 create mode 100644 test/pseudo-tty/test-tty-color-support-warning-2.out
 create mode 100644 test/pseudo-tty/test-tty-color-support-warning.js
 create mode 100644 test/pseudo-tty/test-tty-color-support-warning.out

diff --git a/lib/internal/tty.js b/lib/internal/tty.js
index 98975fa68a436f..44d51737008eb0 100644
--- a/lib/internal/tty.js
+++ b/lib/internal/tty.js
@@ -73,18 +73,26 @@ const TERM_ENVS_REG_EXP = [
   /^vt100/
 ];
 
+let warned = false;
 function warnOnDeactivatedColors(env) {
-  let name;
+  if (warned)
+    return;
+  let name = '';
   if (env.NODE_DISABLE_COLORS !== undefined)
     name = 'NODE_DISABLE_COLORS';
-  if (env.NO_COLOR !== undefined)
-    name = 'NO_COLOR';
+  if (env.NO_COLOR !== undefined) {
+    if (name !== '') {
+      name += "' and '";
+    }
+    name += 'NO_COLOR';
+  }
 
-  if (name !== undefined) {
+  if (name !== '') {
     process.emitWarning(
       `The '${name}' env is ignored due to the 'FORCE_COLOR' env being set.`,
       'Warning'
     );
+    warned = true;
   }
 }
 
diff --git a/test/pseudo-tty/test-tty-color-support-warning-2.js b/test/pseudo-tty/test-tty-color-support-warning-2.js
new file mode 100644
index 00000000000000..34ba49c0dfd1b5
--- /dev/null
+++ b/test/pseudo-tty/test-tty-color-support-warning-2.js
@@ -0,0 +1,8 @@
+'use strict';
+
+require('../common');
+
+process.env.NODE_DISABLE_COLORS = '1';
+process.env.FORCE_COLOR = '3';
+
+console.log();
diff --git a/test/pseudo-tty/test-tty-color-support-warning-2.out b/test/pseudo-tty/test-tty-color-support-warning-2.out
new file mode 100644
index 00000000000000..cd57b3f9f69672
--- /dev/null
+++ b/test/pseudo-tty/test-tty-color-support-warning-2.out
@@ -0,0 +1,2 @@
+
+(node:*) Warning: The 'NODE_DISABLE_COLORS' env is ignored due to the 'FORCE_COLOR' env being set.
diff --git a/test/pseudo-tty/test-tty-color-support-warning.js b/test/pseudo-tty/test-tty-color-support-warning.js
new file mode 100644
index 00000000000000..ae164958d2d6b9
--- /dev/null
+++ b/test/pseudo-tty/test-tty-color-support-warning.js
@@ -0,0 +1,9 @@
+'use strict';
+
+require('../common');
+
+process.env.NO_COLOR = '1';
+process.env.NODE_DISABLE_COLORS = '1';
+process.env.FORCE_COLOR = '3';
+
+console.log();
diff --git a/test/pseudo-tty/test-tty-color-support-warning.out b/test/pseudo-tty/test-tty-color-support-warning.out
new file mode 100644
index 00000000000000..9360ae1328b2cd
--- /dev/null
+++ b/test/pseudo-tty/test-tty-color-support-warning.out
@@ -0,0 +1,2 @@
+
+(node:*) Warning: The 'NODE_DISABLE_COLORS' and 'NO_COLOR' env is ignored due to the 'FORCE_COLOR' env being set.
diff --git a/test/pseudo-tty/test-tty-color-support.out b/test/pseudo-tty/test-tty-color-support.out
index f73fbdcd9651f6..e6904d10b8a7b8 100644
--- a/test/pseudo-tty/test-tty-color-support.out
+++ b/test/pseudo-tty/test-tty-color-support.out
@@ -1,8 +1 @@
 (node:*) Warning: The 'NO_COLOR' env is ignored due to the 'FORCE_COLOR' env being set.
-(node:*) Warning: The 'NO_COLOR' env is ignored due to the 'FORCE_COLOR' env being set.
-(node:*) Warning: The 'NO_COLOR' env is ignored due to the 'FORCE_COLOR' env being set.
-(node:*) Warning: The 'NO_COLOR' env is ignored due to the 'FORCE_COLOR' env being set.
-(node:*) Warning: The 'NODE_DISABLE_COLORS' env is ignored due to the 'FORCE_COLOR' env being set.
-(node:*) Warning: The 'NODE_DISABLE_COLORS' env is ignored due to the 'FORCE_COLOR' env being set.
-(node:*) Warning: The 'NODE_DISABLE_COLORS' env is ignored due to the 'FORCE_COLOR' env being set.
-(node:*) Warning: The 'NODE_DISABLE_COLORS' env is ignored due to the 'FORCE_COLOR' env being set.