win: fix the inconsistency in volume serial number

src/win/fs.c

@@ -1788,7 +1788,7 @@ INLINE static int fs__stat_handle(HANDLE handle, uv_stat_t* statbuf,
     SetLastError(pRtlNtStatusToDosError(nt_status));
     return -1;
   } else {
-    stat_info.VolumeSerialNumber.QuadPart = volume_info.VolumeSerialNumber;
+    stat_info.VolumeSerialNumber.LowPart = volume_info.VolumeSerialNumber;
   }
 
   stat_info.DeviceType = device_info.DeviceType;
@@ -1839,7 +1839,7 @@ INLINE static void fs__stat_assign_statbuf_null(uv_stat_t* statbuf) {
 
 INLINE static void fs__stat_assign_statbuf(uv_stat_t* statbuf,
     FILE_STAT_BASIC_INFORMATION stat_info, int do_lstat) {
-  statbuf->st_dev = stat_info.VolumeSerialNumber.QuadPart;
+  statbuf->st_dev = stat_info.VolumeSerialNumber.LowPart;
 
   /* Todo: st_mode should probably always be 0666 for everyone. We might also
    * want to report 0777 if the file is a .exe or a directory.

test/test-fs.c

@@ -1607,6 +1607,50 @@ TEST_IMPL(fs_fstat) {
 }
 
 
+TEST_IMPL(fs_fstat_st_dev) {
+  uv_fs_t req;
+  uv_fs_t req_link;
+  uv_loop_t* loop = uv_default_loop();
+  char* test_file = "tmp_st_dev";
+  char* symlink_file = "tmp_st_dev_link";
+
+  unlink(test_file);
+  unlink(symlink_file);
+
+  // Create file
+  int r = uv_fs_open(NULL, &req, test_file, UV_FS_O_RDWR | UV_FS_O_CREAT,
+      S_IWUSR | S_IRUSR, NULL);
+  ASSERT_GE(r, 0);
+  ASSERT_GE(req.result, 0);
+  uv_fs_req_cleanup(&req);
+
+  // Create a symlink
+  r = uv_fs_symlink(loop, &req, test_file, symlink_file, 0, NULL);
+  ASSERT_EQ(r, 0);
+  uv_fs_req_cleanup(&req);
+
+  // Call uv_fs_fstat for file
+  r = uv_fs_stat(loop, &req, test_file, NULL);
+  ASSERT_EQ(r, 0);
+
+  // Call uv_fs_fstat for symlink
+  r = uv_fs_stat(loop, &req_link, symlink_file, NULL);
+  ASSERT_EQ(r, 0);
+
+  // Compare st_dev
+  ASSERT_EQ(((uv_stat_t*)req.ptr)->st_dev, ((uv_stat_t*)req_link.ptr)->st_dev);
+
+  // Cleanup
+  uv_fs_req_cleanup(&req);
+  uv_fs_req_cleanup(&req_link);
+  unlink(test_file);
+  unlink(symlink_file);
+
+  MAKE_VALGRIND_HAPPY(loop);
+  return 0;
+}
+
+
 TEST_IMPL(fs_fstat_stdio) {
   int fd;
   int res;

test/test-list.h

@@ -364,6 +364,7 @@ TEST_DECLARE   (fs_mkdtemp)
 TEST_DECLARE   (fs_mkstemp)
 TEST_DECLARE   (fs_fstat)
 TEST_DECLARE   (fs_fstat_stdio)
+TEST_DECLARE   (fs_fstat_st_dev)
 TEST_DECLARE   (fs_access)
 TEST_DECLARE   (fs_chmod)
 TEST_DECLARE   (fs_copyfile)
@@ -1083,6 +1084,7 @@ TASK_LIST_START
   TEST_ENTRY  (fs_mkstemp)
   TEST_ENTRY  (fs_fstat)
   TEST_ENTRY  (fs_fstat_stdio)
+  TEST_ENTRY  (fs_fstat_st_dev)
   TEST_ENTRY  (fs_access)
   TEST_ENTRY  (fs_chmod)
   TEST_ENTRY  (fs_copyfile)