From 2609204b1f3c46ffcff70766423f08a79f0b7e5c Mon Sep 17 00:00:00 2001
From: Robert Nagy <ronagy@icloud.com>
Date: Tue, 13 Apr 2021 00:54:24 +0200
Subject: [PATCH] stream: fix multiple Writable.destroy() calls.

Calling Writable.destroy() multiple times in the same tick
could cause an assertion error.

Fixes: https://github.com/nodejs/node/issues/38189
---
 lib/internal/streams/writable.js              |  4 ++--
 test/parallel/test-stream-writable-destroy.js | 11 +++++++++++
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/lib/internal/streams/writable.js b/lib/internal/streams/writable.js
index 97fe1d28ef1f3a..45de5157ec517b 100644
--- a/lib/internal/streams/writable.js
+++ b/lib/internal/streams/writable.js
@@ -845,10 +845,10 @@ Writable.prototype.destroy = function(err, cb) {
 
   // Invoke pending callbacks.
   if (
+    !state.destroyed && (
     state.bufferedIndex < state.buffered.length ||
     state[kOnFinished].length
-  ) {
-    assert(!state.destroyed);
+  )) {
     process.nextTick(errorBuffer, state);
   }
 
diff --git a/test/parallel/test-stream-writable-destroy.js b/test/parallel/test-stream-writable-destroy.js
index 7cd800b0938138..2e6e1f975a2be1 100644
--- a/test/parallel/test-stream-writable-destroy.js
+++ b/test/parallel/test-stream-writable-destroy.js
@@ -460,3 +460,14 @@ const assert = require('assert');
     assert.strictEqual(write.destroyed, true);
   }));
 }
+
+{
+  // Destroy twice
+  const write = new Writable({
+    write(chunk, enc, cb) { cb(); }
+  });
+
+  write.end(common.mustCall());
+  write.destroy();
+  write.destroy();
+}