--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/third_party/libuv/test/test-udp-dgram-too-big.c	Wed Jan 14 19:39:52 2026 -0800
@@ -0,0 +1,91 @@
+/* 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>
+
+#define CHECK_HANDLE(handle) \
+  ASSERT_PTR_EQ((uv_udp_t*)(handle), &handle_)
+
+#define CHECK_REQ(req) \
+  ASSERT_PTR_EQ((req), &req_);
+
+static uv_udp_t handle_;
+static uv_udp_send_t req_;
+
+static int send_cb_called;
+static int close_cb_called;
+
+
+static void close_cb(uv_handle_t* handle) {
+  CHECK_HANDLE(handle);
+  close_cb_called++;
+}
+
+
+static void send_cb(uv_udp_send_t* req, int status) {
+  CHECK_REQ(req);
+  CHECK_HANDLE(req->handle);
+
+  ASSERT_EQ(status, UV_EMSGSIZE);
+
+  uv_close((uv_handle_t*)req->handle, close_cb);
+  send_cb_called++;
+}
+
+
+TEST_IMPL(udp_dgram_too_big) {
+  char dgram[65536]; /* 64K MTU is unlikely, even on localhost */
+  struct sockaddr_in addr;
+  uv_buf_t buf;
+  int r;
+
+  memset(dgram, 42, sizeof dgram); /* silence valgrind */
+
+  r = uv_udp_init(uv_default_loop(), &handle_);
+  ASSERT_OK(r);
+
+  buf = uv_buf_init(dgram, sizeof dgram);
+  ASSERT_OK(uv_ip4_addr("127.0.0.1", TEST_PORT, &addr));
+
+  r = uv_udp_send(&req_,
+                  &handle_,
+                  &buf,
+                  1,
+                  (const struct sockaddr*) &addr,
+                  send_cb);
+  ASSERT_OK(r);
+
+  ASSERT_OK(close_cb_called);
+  ASSERT_OK(send_cb_called);
+
+  uv_run(uv_default_loop(), UV_RUN_DEFAULT);
+
+  ASSERT_EQ(1, send_cb_called);
+  ASSERT_EQ(1, close_cb_called);
+
+  MAKE_VALGRIND_HAPPY(uv_default_loop());
+  return 0;
+}