Opening a dialog causes a panic

[VZout]

With the latest winit version opening a dialog using nfd2 causes a panic.
Reverting #1496 fixes it.

I'll investigate this further, repro in a example and PR a fix.

[Jake-Shadle]

To be clear, it's a panic, not a crash, here is the relevant stack trace and panic message.

either event handler is re-entrant (likely), or no event handler is registered (very unlikely), file: C:\Users\viktor.zoutman\.cargo\registry\src\github.com-1ecc6299db9ec823\winit-0.22.2\src\platform_impl\windows\event_loop\runner.rs:235:37, thread: main

Thread 0
0   core                            0x7ff628925ff0      core::panicking::panic_fmt (panicking.rs:101)
1   core                            0x7ff628925d42      core::option::expect_failed (option.rs:1264)
2   core                            0x7ff628e9387b      core::option::Option<T>::expect<T> (option.rs:349)
3   winit                           0x7ff6295ec7e4      winit::platform_impl::platform::event_loop::runner::{{impl}}::call_event_handler::{{closure}}<T> (runner.rs:235)
4   std                             0x7ff628c4fba6      std::panic::{{impl}}::call_once<T> (panic.rs:318)
5   std                             0x7ff628c8ae10      std::panicking::try::do_call<T> (panicking.rs:297)
6   winit                           0x7ff628c8f387      winit::window::{{impl}}::clone
7   std                             0x7ff628c8aa8a      std::panicking::try<T> (panicking.rs:274)
8   std                             0x7ff628c50a46      std::panic::catch_unwind<T> (panic.rs:394)
9   winit                           0x7ff6295ebe09      winit::platform_impl::platform::event_loop::runner::EventLoopRunner<T>::catch_unwind<T> (runner.rs:150)
10  winit                           0x7ff6295ec741      winit::platform_impl::platform::event_loop::runner::EventLoopRunner<T>::call_event_handler<T> (runner.rs:233)
11  winit                           0x7ff6295ed5f5      winit::platform_impl::platform::event_loop::runner::EventLoopRunner<T>::call_new_events<T> (runner.rs:360)
12  winit                           0x7ff6295ecf75      winit::platform_impl::platform::event_loop::runner::EventLoopRunner<T>::move_state_to<T> (runner.rs:299)
13  winit                           0x7ff6295ec6c3      winit::platform_impl::platform::event_loop::runner::EventLoopRunner<T>::main_events_cleared<T> (runner.rs:225)
14  winit                           0x7ff628d0d898      winit::platform_impl::platform::event_loop::flush_paint_messages<T> (event_loop.rs:663)
15  winit                           0x7ff628d0dde1      winit::platform_impl::platform::event_loop::thread_event_target_callback::{{closure}}<T> (event_loop.rs:1938)
16  std                             0x7ff628c4fb53      std::panic::{{impl}}::call_once<T> (panic.rs:318)
17  std                             0x7ff628c8ae7e      std::panicking::try::do_call<T> (panicking.rs:297)
18  winit                           0x7ff628c8f387      winit::window::{{impl}}::clone
19  std                             0x7ff628c8acc3      std::panicking::try<T> (panicking.rs:274)
20  std                             0x7ff628c509fe      std::panic::catch_unwind<T> (panic.rs:394)
21  winit                           0x7ff6295eb9b3      winit::platform_impl::platform::event_loop::runner::EventLoopRunner<T>::catch_unwind<T> (runner.rs:150)
22  winit                           0x7ff628d0dc51      winit::platform_impl::platform::event_loop::thread_event_target_callback<T> (event_loop.rs:2120)
23  <unknown>                       0x7fff4d65d3b6      DefSubclassProc
24  <unknown>                       0x7fff4d65d26c      DefSubclassProc
25  <unknown>                       0x7fff6546e338      CallWindowProcW
26  <unknown>                       0x7fff6546debc      DispatchMessageW
27  <unknown>                       0x7fff654806a3      SendMessageTimeoutW
28  <unknown>                       0x7fff66fefbf4      KiUserCallbackDispatcher
29  <unknown>                       0x7fff64d61704      NtUserDispatchMessage
30  <unknown>                       0x7fff6546ddca      DispatchMessageW
31  <unknown>                       0x7fff6548d231      DialogBoxIndirectParamAorW
32  <unknown>                       0x7fff6548cea1      DialogBoxIndirectParamAorW
33  <unknown>                       0x7fff6548cd52      DialogBoxIndirectParamAorW
34  <unknown>                       0x7fff6548cce8      DialogBoxIndirectParamW
35  <unknown>                       0x7fff65b05c56      <unknown>
36  <unknown>                       0x7fff65ae2804      <unknown>
37  <unknown>                       0x7ff62c645b46      NFD_PickFolder (nfd_win.cpp:710)
38  nfd2                            0x7ff62a699e2d      nfd2::open_dialog (lib.rs:227)
39  nfd2                            0x7ff62a699975      nfd2::open_pick_folder (lib.rs:179)

[alvinhochun]

Isn't this the same as #1602?