--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/third_party/libuv/test/test-tcp-write-to-half-open-connection.c	Wed Jan 14 19:39:52 2026 -0800
@@ -0,0 +1,141 @@
+/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include "uv.h"
+#include "task.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+static void connection_cb(uv_stream_t* server, int status);
+static void connect_cb(uv_connect_t* req, int status);
+static void write_cb(uv_write_t* req, int status);
+static void read_cb(uv_stream_t* stream, ssize_t nread, const uv_buf_t* buf);
+static void alloc_cb(uv_handle_t* handle, size_t suggested_size, uv_buf_t* buf);
+
+static uv_tcp_t tcp_server;
+static uv_tcp_t tcp_client;
+static uv_tcp_t tcp_peer; /* client socket as accept()-ed by server */
+static uv_connect_t connect_req;
+static uv_write_t write_req;
+
+static int write_cb_called;
+static int read_cb_called;
+
+static void connection_cb(uv_stream_t* server, int status) {
+  int r;
+  uv_buf_t buf;
+
+  ASSERT_PTR_EQ(server, (uv_stream_t*)&tcp_server);
+  ASSERT_OK(status);
+
+  r = uv_tcp_init(server->loop, &tcp_peer);
+  ASSERT_OK(r);
+
+  r = uv_accept(server, (uv_stream_t*)&tcp_peer);
+  ASSERT_OK(r);
+
+  r = uv_read_start((uv_stream_t*)&tcp_peer, alloc_cb, read_cb);
+  ASSERT_OK(r);
+
+  buf.base = "hello\n";
+  buf.len = 6;
+
+  r = uv_write(&write_req, (uv_stream_t*)&tcp_peer, &buf, 1, write_cb);
+  ASSERT_OK(r);
+}
+
+
+static void alloc_cb(uv_handle_t* handle,
+                     size_t suggested_size,
+                     uv_buf_t* buf) {
+  static char slab[1024];
+  buf->base = slab;
+  buf->len = sizeof(slab);
+}
+
+
+static void read_cb(uv_stream_t* stream, ssize_t nread, const uv_buf_t* buf) {
+  if (nread < 0) {
+    fprintf(stderr, "read_cb error: %s\n", uv_err_name(nread));
+    ASSERT(nread == UV_ECONNRESET || nread == UV_EOF);
+
+    uv_close((uv_handle_t*)&tcp_server, NULL);
+    uv_close((uv_handle_t*)&tcp_peer, NULL);
+  }
+
+  read_cb_called++;
+}
+
+
+static void connect_cb(uv_connect_t* req, int status) {
+  ASSERT_PTR_EQ(req, &connect_req);
+  ASSERT_OK(status);
+
+  /* Close the client. */
+  uv_close((uv_handle_t*)&tcp_client, NULL);
+}
+
+
+static void write_cb(uv_write_t* req, int status) {
+  ASSERT_OK(status);
+  write_cb_called++;
+}
+
+
+TEST_IMPL(tcp_write_to_half_open_connection) {
+  struct sockaddr_in addr;
+  uv_loop_t* loop;
+  int r;
+
+  ASSERT_OK(uv_ip4_addr("127.0.0.1", TEST_PORT, &addr));
+
+  loop = uv_default_loop();
+  ASSERT_NOT_NULL(loop);
+
+  r = uv_tcp_init(loop, &tcp_server);
+  ASSERT_OK(r);
+
+  r = uv_tcp_bind(&tcp_server, (const struct sockaddr*) &addr, 0);
+  ASSERT_OK(r);
+
+  r = uv_listen((uv_stream_t*)&tcp_server, 1, connection_cb);
+  ASSERT_OK(r);
+
+  r = uv_tcp_init(loop, &tcp_client);
+  ASSERT_OK(r);
+
+  r = uv_tcp_connect(&connect_req,
+                     &tcp_client,
+                     (const struct sockaddr*) &addr,
+                     connect_cb);
+  ASSERT_OK(r);
+
+  r = uv_run(loop, UV_RUN_DEFAULT);
+  ASSERT_OK(r);
+
+  ASSERT_GT(write_cb_called, 0);
+  ASSERT_GT(read_cb_called, 0);
+
+  MAKE_VALGRIND_HAPPY(loop);
+  return 0;
+}