From c224e1b25565d89e30f4ca873a31bd22bbd6f29e Mon Sep 17 00:00:00 2001
From: Robert Nagy <ronagy@icloud.com>
Date: Wed, 12 Jul 2023 15:31:49 +0100
Subject: [PATCH] stream: fix deadlock when pipeing to full sink

When piping a paused Readable to a full Writable we didn't
register a drain listener which cause the src to never
resume.

Refs: https://github.com/nodejs/node/issues/48666
PR-URL: https://github.com/nodejs/node/pull/48691
Backport-PR-URL: https://github.com/nodejs/node/pull/49323
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
---
 lib/internal/streams/readable.js           |  4 +---
 test/parallel/test-stream-pipe-deadlock.js | 27 ++++++++++++++++++++++
 2 files changed, 28 insertions(+), 3 deletions(-)
 create mode 100644 test/parallel/test-stream-pipe-deadlock.js

diff --git a/lib/internal/streams/readable.js b/lib/internal/streams/readable.js
index 05ba2400fa6e9f..3b91ff9852baca 100644
--- a/lib/internal/streams/readable.js
+++ b/lib/internal/streams/readable.js
@@ -814,9 +814,7 @@ Readable.prototype.pipe = function(dest, pipeOpts) {
   // Start the flow if it hasn't been started already.
 
   if (dest.writableNeedDrain === true) {
-    if (state.flowing) {
-      pause();
-    }
+    pause();
   } else if (!state.flowing) {
     debug('pipe resume');
     src.resume();
diff --git a/test/parallel/test-stream-pipe-deadlock.js b/test/parallel/test-stream-pipe-deadlock.js
new file mode 100644
index 00000000000000..bf75445877baef
--- /dev/null
+++ b/test/parallel/test-stream-pipe-deadlock.js
@@ -0,0 +1,27 @@
+'use strict';
+
+const common = require('../common');
+const { Readable, Writable } = require('stream');
+
+// https://github.com/nodejs/node/issues/48666
+(async () => {
+  // Prepare src that is internally ended, with buffered data pending
+  const src = new Readable({ read() {} });
+  src.push(Buffer.alloc(100));
+  src.push(null);
+  src.pause();
+
+  // Give it time to settle
+  await new Promise((resolve) => setImmediate(resolve));
+
+  const dst = new Writable({
+    highWaterMark: 1000,
+    write(buf, enc, cb) {
+      process.nextTick(cb);
+    }
+  });
+
+  dst.write(Buffer.alloc(1000)); // Fill write buffer
+  dst.on('finish', common.mustCall());
+  src.pipe(dst);
+})().then(common.mustCall());