--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/third_party/libuv/test/test-tcp-rst.c	Wed Jan 14 19:39:52 2026 -0800
@@ -0,0 +1,110 @@
+/* Copyright libuv project and 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"
+
+static uv_tcp_t tcp;
+static uv_connect_t connect_req;
+static uv_buf_t qbuf;
+static int called_alloc_cb;
+static int called_connect_cb;
+static int called_close_cb;
+
+
+static void close_cb(uv_handle_t* handle) {
+  ASSERT_PTR_EQ(handle, (uv_handle_t*) &tcp);
+  called_close_cb++;
+}
+
+
+static void alloc_cb(uv_handle_t* handle, size_t size, uv_buf_t* buf) {
+  buf->base = malloc(size);
+  buf->len = size;
+  called_alloc_cb++;
+}
+
+
+static void read_cb(uv_stream_t* t, ssize_t nread, const uv_buf_t* buf) {
+  ASSERT_PTR_EQ((uv_tcp_t*) t, &tcp);
+  ASSERT_EQ(nread, UV_ECONNRESET);
+
+  int fd;
+  ASSERT_OK(uv_fileno((uv_handle_t*) t, &fd));
+  uv_handle_type type = uv_guess_handle(fd);
+  ASSERT_EQ(type, UV_TCP);
+
+  uv_close((uv_handle_t *) t, close_cb);
+  free(buf->base);
+}
+
+
+static void connect_cb(uv_connect_t *req, int status) {
+  ASSERT_OK(status);
+  ASSERT_PTR_EQ(req, &connect_req);
+
+  /* Start reading from the connection so we receive the RST in uv__read. */
+  ASSERT_OK(uv_read_start((uv_stream_t*) &tcp, alloc_cb, read_cb));
+
+  /* Write 'QSH' to receive RST from the echo server. */
+  ASSERT_EQ(qbuf.len, uv_try_write((uv_stream_t*) &tcp, &qbuf, 1));
+
+  called_connect_cb++;
+}
+
+
+/*
+ * This test has a client which connects to the echo_server and receives TCP
+ * RST. Test checks that uv_guess_handle still works on a reset TCP handle.
+ */
+TEST_IMPL(tcp_rst) {
+#if defined(__OpenBSD__)
+  RETURN_SKIP("Test does not currently work in OpenBSD");
+#endif
+#ifndef _WIN32
+  struct sockaddr_in server_addr;
+  int r;
+
+  qbuf.base = "QSH";
+  qbuf.len = 3;
+
+  ASSERT_OK(uv_ip4_addr("127.0.0.1", TEST_PORT, &server_addr));
+  r = uv_tcp_init(uv_default_loop(), &tcp);
+  ASSERT_OK(r);
+
+  r = uv_tcp_connect(&connect_req,
+                     &tcp,
+                     (const struct sockaddr*) &server_addr,
+                     connect_cb);
+  ASSERT_OK(r);
+
+  uv_run(uv_default_loop(), UV_RUN_DEFAULT);
+
+  ASSERT_EQ(1, called_alloc_cb);
+  ASSERT_EQ(1, called_connect_cb);
+  ASSERT_EQ(1, called_close_cb);
+
+  MAKE_VALGRIND_HAPPY(uv_default_loop());
+  return 0;
+#else
+  RETURN_SKIP("Unix only test");
+#endif
+}