From d4ceb59d88d105a4bb6127b26403e8052977abb3 Mon Sep 17 00:00:00 2001
From: Christopher Luke <zaide@zaidesthings.com>
Date: Wed, 15 Mar 2017 22:53:35 -0700
Subject: [PATCH] stream: Fixes missing 'unpipe' event

Currently when the destination emits an 'error', 'finish' or 'close'
event the pipe calls unpipe to emit 'unpipe' and trigger the clean up
of all it's listeners.
When the source emits an 'end' event without {end: false} it calls
end() on the destination leading it to emit a 'close', this will again
lead to the pipe calling unpipe. However the source emitting an 'end'
event along side {end: false} is the only time the cleanup gets ran
directly without unpipe being called. This fixes that so the 'unpipe'
event does get emitted and cleanup in turn gets ran by that event.

Fixes: https://github.com/nodejs/node/issues/11837
PR-URL: https://github.com/nodejs/node/pull/11876
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
---
 lib/_stream_readable.js                   |  4 +-
 test/parallel/test-stream-unpipe-event.js | 87 +++++++++++++++++++++++
 2 files changed, 89 insertions(+), 2 deletions(-)
 create mode 100644 test/parallel/test-stream-unpipe-event.js

diff --git a/lib/_stream_readable.js b/lib/_stream_readable.js
index e33441971fe746..9be18350560229 100644
--- a/lib/_stream_readable.js
+++ b/lib/_stream_readable.js
@@ -494,7 +494,7 @@ Readable.prototype.pipe = function(dest, pipeOpts) {
               dest !== process.stdout &&
               dest !== process.stderr;
 
-  var endFn = doEnd ? onend : cleanup;
+  var endFn = doEnd ? onend : unpipe;
   if (state.endEmitted)
     process.nextTick(endFn);
   else
@@ -530,7 +530,7 @@ Readable.prototype.pipe = function(dest, pipeOpts) {
     dest.removeListener('error', onerror);
     dest.removeListener('unpipe', onunpipe);
     src.removeListener('end', onend);
-    src.removeListener('end', cleanup);
+    src.removeListener('end', unpipe);
     src.removeListener('data', ondata);
 
     cleanedUp = true;
diff --git a/test/parallel/test-stream-unpipe-event.js b/test/parallel/test-stream-unpipe-event.js
new file mode 100644
index 00000000000000..a9e634a11a3092
--- /dev/null
+++ b/test/parallel/test-stream-unpipe-event.js
@@ -0,0 +1,87 @@
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+const {Writable, Readable} = require('stream');
+class NullWriteable extends Writable {
+  _write(chunk, encoding, callback) {
+    return callback();
+  }
+}
+class QuickEndReadable extends Readable {
+  _read() {
+    this.push(null);
+  }
+}
+class NeverEndReadable extends Readable {
+  _read() {}
+}
+
+function noop() {}
+
+{
+  const dest = new NullWriteable();
+  const src = new QuickEndReadable();
+  dest.on('pipe', common.mustCall(noop));
+  dest.on('unpipe', common.mustCall(noop));
+  src.pipe(dest);
+  setImmediate(() => {
+    assert.strictEqual(src._readableState.pipesCount, 0);
+  });
+}
+
+{
+  const dest = new NullWriteable();
+  const src = new NeverEndReadable();
+  dest.on('pipe', common.mustCall(noop));
+  dest.on('unpipe', common.mustNotCall('unpipe should not have been emitted'));
+  src.pipe(dest);
+  setImmediate(() => {
+    assert.strictEqual(src._readableState.pipesCount, 1);
+  });
+}
+
+{
+  const dest = new NullWriteable();
+  const src = new NeverEndReadable();
+  dest.on('pipe', common.mustCall(noop));
+  dest.on('unpipe', common.mustCall(noop));
+  src.pipe(dest);
+  src.unpipe(dest);
+  setImmediate(() => {
+    assert.strictEqual(src._readableState.pipesCount, 0);
+  });
+}
+
+{
+  const dest = new NullWriteable();
+  const src = new QuickEndReadable();
+  dest.on('pipe', common.mustCall(noop));
+  dest.on('unpipe', common.mustCall(noop));
+  src.pipe(dest, {end: false});
+  setImmediate(() => {
+    assert.strictEqual(src._readableState.pipesCount, 0);
+  });
+}
+
+{
+  const dest = new NullWriteable();
+  const src = new NeverEndReadable();
+  dest.on('pipe', common.mustCall(noop));
+  dest.on('unpipe', common.mustNotCall('unpipe should not have been emitted'));
+  src.pipe(dest, {end: false});
+  setImmediate(() => {
+    assert.strictEqual(src._readableState.pipesCount, 1);
+  });
+}
+
+{
+  const dest = new NullWriteable();
+  const src = new NeverEndReadable();
+  dest.on('pipe', common.mustCall(noop));
+  dest.on('unpipe', common.mustCall(noop));
+  src.pipe(dest, {end: false});
+  src.unpipe(dest);
+  setImmediate(() => {
+    assert.strictEqual(src._readableState.pipesCount, 0);
+  });
+}