From bed0560fb5e7172e71476713042d5f8ba77fdf2e Mon Sep 17 00:00:00 2001
From: Matteo Collina <hello@matteocollina.com>
Date: Sun, 5 Nov 2017 12:26:27 +0000
Subject: [PATCH] console: avoid adding infinite error listeners

If the console destination is a unix pipe (net.Socket), write() is
async. If the destination is broken, we are adding an 'error' event
listener to avoid a process crash. This PR makes sure that we are adding
that listener only once.

Fixes: https://github.com/nodejs/node/issues/16767

PR-URL: https://github.com/nodejs/node/pull/16770
Fixes: https://github.com/nodejs/node/issues/16767
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Sam Roberts <vieuxtech@gmail.com>
---
 lib/console.js                                |  5 +++-
 .../test-console-log-stdio-broken-dest.js     | 24 +++++++++++++++++++
 2 files changed, 28 insertions(+), 1 deletion(-)
 create mode 100644 test/parallel/test-console-log-stdio-broken-dest.js

diff --git a/lib/console.js b/lib/console.js
index 54c8aba8299565..2304a6668790de 100644
--- a/lib/console.js
+++ b/lib/console.js
@@ -83,7 +83,10 @@ function createWriteErrorHandler(stream) {
       // an `error` event. Adding a `once` listener will keep that error
       // from becoming an uncaught exception, but since the handler is
       // removed after the event, non-console.* writes won’t be affected.
-      stream.once('error', noop);
+      // we are only adding noop if there is no one else listening for 'error'
+      if (stream.listenerCount('error') === 0) {
+        stream.on('error', noop);
+      }
     }
   };
 }
diff --git a/test/parallel/test-console-log-stdio-broken-dest.js b/test/parallel/test-console-log-stdio-broken-dest.js
new file mode 100644
index 00000000000000..d29e8ee5173be7
--- /dev/null
+++ b/test/parallel/test-console-log-stdio-broken-dest.js
@@ -0,0 +1,24 @@
+'use strict';
+
+const common = require('../common');
+const { Writable } = require('stream');
+const { Console } = require('console');
+const { EventEmitter } = require('events');
+
+const stream = new Writable({
+  write(chunk, enc, cb) {
+    cb();
+  },
+  writev(chunks, cb) {
+    setTimeout(cb, 10, new Error('kaboom'));
+  }
+});
+const myConsole = new Console(stream, stream);
+
+process.on('warning', common.mustNotCall);
+
+stream.cork();
+for (let i = 0; i < EventEmitter.defaultMaxListeners + 1; i++) {
+  myConsole.log('a message');
+}
+stream.uncork();