From 431638d4fefebb400926aa11f5482b42f3e5059f Mon Sep 17 00:00:00 2001
From: Anna Henningsen <anna@addaleax.net>
Date: Tue, 18 Oct 2016 22:30:03 +0200
Subject: [PATCH 1/3] streams: fix regression in `unpipe()`

Since 2e568d9 there is a bug where unpiping a stream
from a readable stream that has `_readableState.pipesCount > 1`
will cause it to remove the first stream in the
`_.readableState.pipes` array no matter where in the list the
`dest` stream was.

This patch corrects that problem.

Fixes: https://github.com/nodejs/node/issues/9170
---
 lib/_stream_readable.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/_stream_readable.js b/lib/_stream_readable.js
index 9438bf92d34ee2..0844604d960258 100644
--- a/lib/_stream_readable.js
+++ b/lib/_stream_readable.js
@@ -671,7 +671,7 @@ Readable.prototype.unpipe = function(dest) {
   if (index === -1)
     return this;
 
-  state.pipes.splice(i, 1);
+  state.pipes.splice(index, 1);
   state.pipesCount -= 1;
   if (state.pipesCount === 1)
     state.pipes = state.pipes[0];

From b41cf22fbee064bef7fdcd44848ae6907e89bee4 Mon Sep 17 00:00:00 2001
From: Niels Nielsen <niels@protectwise.com>
Date: Tue, 18 Oct 2016 22:30:03 +0200
Subject: [PATCH 2/3] test: add regression test for `unpipe()`

Since 2e568d9 there is a bug where unpiping a stream
from a readable stream that has `_readableState.pipesCount > 1`
will cause it to remove the first stream in the
`_.readableState.pipes` array no matter where in the list the
`dest` stream was.
---
 .../test-stream-pipe-unpipe-streams.js        | 26 +++++++++++++++++++
 1 file changed, 26 insertions(+)
 create mode 100644 test/parallel/test-stream-pipe-unpipe-streams.js

diff --git a/test/parallel/test-stream-pipe-unpipe-streams.js b/test/parallel/test-stream-pipe-unpipe-streams.js
new file mode 100644
index 00000000000000..55362253063abd
--- /dev/null
+++ b/test/parallel/test-stream-pipe-unpipe-streams.js
@@ -0,0 +1,26 @@
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+
+const { Readable, Writable } = require('stream');
+
+const source = Readable({read: () => {}});
+const dest1 = Writable({write: () => {}});
+const dest2 = Writable({write: () => {}});
+
+source.pipe(dest1);
+source.pipe(dest2);
+
+dest1.on('unpipe', common.mustCall(() => {}));
+dest2.on('unpipe', common.mustCall(() => {}));
+
+// Should be able to unpipe them in the reverse order that they were piped.
+
+source.unpipe(dest2);
+
+assert.strictEqual(source._readableState.pipes, dest1);
+assert.notStrictEqual(source._readableState.pipes, dest2);
+
+source.unpipe(dest1);
+
+assert.strictEqual(source._readableState.pipes, null);

From f140c3f6be29f94fa0d6fa75df8006c1bf826bae Mon Sep 17 00:00:00 2001
From: Anna Henningsen <anna@addaleax.net>
Date: Tue, 18 Oct 2016 23:14:12 +0200
Subject: [PATCH 3/3] [squash] addres nit for checking `_readableState.pipes`
 before unpiping

---
 test/parallel/test-stream-pipe-unpipe-streams.js | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/test/parallel/test-stream-pipe-unpipe-streams.js b/test/parallel/test-stream-pipe-unpipe-streams.js
index 55362253063abd..c51c100d0f6802 100644
--- a/test/parallel/test-stream-pipe-unpipe-streams.js
+++ b/test/parallel/test-stream-pipe-unpipe-streams.js
@@ -14,6 +14,10 @@ source.pipe(dest2);
 dest1.on('unpipe', common.mustCall(() => {}));
 dest2.on('unpipe', common.mustCall(() => {}));
 
+assert.strictEqual(source._readableState.pipes[0], dest1);
+assert.strictEqual(source._readableState.pipes[1], dest2);
+assert.strictEqual(source._readableState.pipes.length, 2);
+
 // Should be able to unpipe them in the reverse order that they were piped.
 
 source.unpipe(dest2);