From 9d88a60e68720a558773b078887b269cd3b30497 Mon Sep 17 00:00:00 2001
From: Matteo Collina <hello@matteocollina.com>
Date: Sun, 13 Sep 2026 15:33:31 +0000
Subject: [PATCH] http2: settle pending write callbacks on destroy

When a stream is destroyed while a write is still in flight, nghttp2 may
have handed the data to the socket and never report the write completion
once the stream or session tears down. That leaves the write callback
unresolved, the Writable stuck, and the event loop never drains, which
times out test-http2-close-while-writing on macOS.

Settle the in-flight write in Http2Stream._destroy by invoking its
callback with the destroy error and resetting writePending. A later
native completion callback is then a no-op because writeCb is null and
writePending is 0, so the settle is idempotent. Passing the error rather
than null also drains any buffered writes.

Fixes: https://github.com/nodejs/node/issues/58252

Signed-off-by: Matteo Collina <hello@matteocollina.com>
Assisted-by: pi-coding-agent
---
 lib/internal/http2/core.js                      |  9 +++++++++
 test/parallel/test-http2-close-while-writing.js | 14 ++++++++++++--
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/lib/internal/http2/core.js b/lib/internal/http2/core.js
index 4700120b0dd4..43169834ff5a 100644
--- a/lib/internal/http2/core.js
+++ b/lib/internal/http2/core.js
@@ -2721,6 +2721,15 @@ class Http2Stream extends Duplex {
         });
       }
     }
+
+    // A write in flight may never get its native completion callback once the
+    // stream tears down; settle it so the Writable can clean up.
+    if (state.writeCb !== null) {
+      const writeCb = state.writeCb;
+      state.writeCb = null;
+      state.writePending = 0;
+      writeCb(err);
+    }
     callback(err);
   }
   // The Http2Stream can be destroyed if it has closed and if the readable
diff --git a/test/parallel/test-http2-close-while-writing.js b/test/parallel/test-http2-close-while-writing.js
index 17931005dc6c..c78386c85f23 100644
--- a/test/parallel/test-http2-close-while-writing.js
+++ b/test/parallel/test-http2-close-while-writing.js
@@ -29,11 +29,21 @@ server.on('session', common.mustCall(function(session) {
     stream.on('error', common.mustCall((err) => {
       assert.strictEqual(err.code, 'ERR_HTTP2_STREAM_ABORTED');
     }));
-    stream.resume();
+
+    // Every write dispatched before close must have its callback invoked.
+    let writes = 0;
+    let writeCallbacks = 0;
     stream.on('data', function() {
-      this.write(Buffer.alloc(1));
+      writes++;
+      this.write(Buffer.alloc(1), () => {
+        writeCallbacks++;
+      });
       process.nextTick(() => client_stream.destroy());
     });
+    stream.on('close', common.mustCall(() => {
+      assert.strictEqual(writeCallbacks, writes);
+    }));
+    stream.resume();
   }));
 }));