From c16f526f55637a0063975755a15c9c10a1eb4c9e Mon Sep 17 00:00:00 2001
From: Matteo Collina <hello@matteocollina.com>
Date: Sat, 14 Feb 2026 12:06:55 +0100
Subject: [PATCH] http2: invoke pending write callback on stream destroy
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When an HTTP/2 stream is destroyed while a write is in progress, the
pending write callback may never be called if the write data has already
been consumed by nghttp2 and moved to the session's outgoing_buffers_.
In this case, the C++ side's SetImmediate cleanup finds nothing in the
stream's write queue, and the callback depends on session socket write
completion — which may never happen during shutdown.

This leaves the Writable stream's internal state stuck, preventing
cleanup of buffered writes and keeping references alive that block
event loop exit.

Track the pending write callback on the stream and invoke it in
_destroy() before calling handle.destroy(), ensuring the Writable
stream can clean up properly. The callback is made idempotent so
duplicate invocations from the C++ side are harmless no-ops.

Fixes: https://github.com/nodejs/node/issues/58252
Refs: https://github.com/nodejs/node/pull/58253
---
 lib/internal/http2/core.js | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/lib/internal/http2/core.js b/lib/internal/http2/core.js
index 8b526c001004c5..242d337fd4b110 100644
--- a/lib/internal/http2/core.js
+++ b/lib/internal/http2/core.js
@@ -253,6 +253,7 @@ const kOptions = Symbol('options');
 const kOwner = owner_symbol;
 const kOrigin = Symbol('origin');
 const kPendingRequestCalls = Symbol('kPendingRequestCalls');
+const kPendingWriteCb = Symbol('kPendingWriteCb');
 const kProceed = Symbol('proceed');
 const kRemoteSettings = Symbol('remote-settings');
 const kRequestAsyncResource = Symbol('requestAsyncResource');
@@ -2276,10 +2277,13 @@ class Http2Stream extends Duplex {
       cb(err);
     };
     const writeCallback = (err) => {
+      if (!waitingForWriteCallback) return;
+      this[kPendingWriteCb] = null;
       waitingForWriteCallback = false;
       writeCallbackErr = err;
       done();
     };
+    this[kPendingWriteCb] = writeCallback;
     const endCheckCallback = (err) => {
       waitingForEndCheck = false;
       endCheckCallbackErr = err;
@@ -2445,6 +2449,12 @@ class Http2Stream extends Duplex {
       closeStream(this, code, hasHandle ? kForceRstStream : kNoRstStream);
     this.push(null);
 
+    const pendingWriteCb = this[kPendingWriteCb];
+    if (pendingWriteCb) {
+      this[kPendingWriteCb] = null;
+      pendingWriteCb(err);
+    }
+
     if (hasHandle) {
       handle.destroy();
       sessionState.streams.delete(id);