--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/third_party/libuv/test/test-udp-multicast-interface6.c	Wed Jan 14 19:39:52 2026 -0800
@@ -0,0 +1,108 @@
+/* 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_NE((uv_udp_t*)(handle) == &server || (uv_udp_t*)(handle) == &client, 0)
+
+static uv_udp_t server;
+static uv_udp_t client;
+
+static int sv_send_cb_called;
+static int close_cb_called;
+
+
+static void close_cb(uv_handle_t* handle) {
+  CHECK_HANDLE(handle);
+  close_cb_called++;
+}
+
+
+static void sv_send_cb(uv_udp_send_t* req, int status) {
+  ASSERT_NOT_NULL(req);
+  ASSERT_OK(status);
+  CHECK_HANDLE(req->handle);
+
+  sv_send_cb_called++;
+
+  uv_close((uv_handle_t*) req->handle, close_cb);
+}
+
+
+TEST_IMPL(udp_multicast_interface6) {
+/* TODO(gengjiawen): Fix test on QEMU. */
+#if defined(__QEMU__)
+  RETURN_SKIP("Test does not currently work in QEMU");
+#endif
+
+  int r;
+  uv_udp_send_t req;
+  uv_buf_t buf;
+  struct sockaddr_in6 addr;
+  struct sockaddr_in6 baddr;
+
+  if (!can_ipv6())
+    RETURN_SKIP("IPv6 not supported");
+
+  ASSERT_OK(uv_ip6_addr("::1", TEST_PORT, &addr));
+
+  r = uv_udp_init(uv_default_loop(), &server);
+  ASSERT_OK(r);
+
+  ASSERT_OK(uv_ip6_addr("::", 0, &baddr));
+  r = uv_udp_bind(&server, (const struct sockaddr*)&baddr, 0);
+  ASSERT_OK(r);
+
+#if defined(__APPLE__) || defined(__FreeBSD__)
+  r = uv_udp_set_multicast_interface(&server, "::1%lo0");
+#else
+  r = uv_udp_set_multicast_interface(&server, NULL);
+#endif
+  ASSERT_OK(r);
+
+  /* server sends "PING" */
+  buf = uv_buf_init("PING", 4);
+  r = uv_udp_send(&req,
+                  &server,
+                  &buf,
+                  1,
+                  (const struct sockaddr*)&addr,
+                  sv_send_cb);
+  ASSERT_OK(r);
+
+  ASSERT_OK(close_cb_called);
+  ASSERT_OK(sv_send_cb_called);
+
+  /* run the loop till all events are processed */
+  uv_run(uv_default_loop(), UV_RUN_DEFAULT);
+
+  ASSERT_EQ(1, sv_send_cb_called);
+  ASSERT_EQ(1, close_cb_called);
+
+  MAKE_VALGRIND_HAPPY(uv_default_loop());
+  return 0;
+}