Crash on changing tab to horiziontal layout

[Wumpf]

Happened in objectron when going from tabbed layout to horizontal

hread 'ThreadId(1)' panicked at 'insertion index (is 18446744073709551614) should be <= len (is 1)', alloc/src/vec/mod.rs:1451

   8: core::panicking::panic_fmt
             at core/src/panicking.rs:64:14
   9: alloc::vec::Vec<T,A>::insert::assert_failed
             at alloc/src/vec/mod.rs:1451:13
  10: egui_tiles::tree::Tree<Pane>::move_tile
  11: egui_tiles::tree::Tree<Pane>::preview_dragged_tile
             at 0127ad5/src/tree.rs:308:17
  12: egui_tiles::tree::Tree<Pane>::ui
             at 0127ad5/src/tree.rs:193:9
  13: re_viewport::viewport::Viewport::viewport_ui::{{closure}}
             at re_viewport/src/viewport.rs:559:13
      core::ops::function::FnOnce::call_once{{vtable.shim}}
             at core/src/ops/function.rs:250:5
  14: <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once
             at alloc/src/boxed.rs:1987:9
  15: egui::ui::Ui::scope_dyn
             at egui-0.22.0/src/ui.rs:1732:19
  16: egui::ui::Ui::scope
             at egui-0.22.0/src/ui.rs:1720:9
      re_viewport::viewport::Viewport::viewport_ui
             at re_viewport/src/viewport.rs:549:9
  17: <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once
             at alloc/src/boxed.rs:1987:9
  18: <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once
             at alloc/src/boxed.rs:1987:9
      egui::containers::frame::Frame::show_dyn
             at egui-0.22.0/src/containers/frame.rs:225:19
  19: core::ops::function::FnOnce::call_once{{vtable.shim}}
  20: <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once
             at alloc/src/boxed.rs:1987:9
  21: <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once
             at alloc/src/boxed.rs:1987:9
      egui::containers::frame::Frame::show_dyn
             at egui-0.22.0/src/containers/frame.rs:225:19
  22: egui::containers::panel::CentralPanel::show_inside_dyn
  23: re_viewer::app_state::AppState::show
  24: core::ops::function::FnOnce::call_once{{vtable.shim}}
  25: <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once
             at alloc/src/boxed.rs:1987:9
  26: <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once
             at alloc/src/boxed.rs:1987:9
      egui::containers::frame::Frame::show_dyn
             at egui-0.22.0/src/containers/frame.rs:225:19
  27: egui::containers::panel::CentralPanel::show_inside_dyn
  28: egui::containers::panel::CentralPanel::show_dyn
  29: <re_viewer::app::App as eframe::epi::App>::update
  30: eframe::native::epi_integration::EpiIntegration::update::{{closure}}
             at eframe-0.22.0/src/native/epi_integration.rs:500:13
      egui::context::Context::run
             at egui-0.22.0/src/context.rs:374:9
  31: eframe::native::epi_integration::EpiIntegration::update
             at eframe-0.22.0/src/native/epi_integration.rs:498:27
  32: <eframe::native::run::wgpu_integration::WgpuWinitApp as eframe::native::run::WinitApp>::run_ui_and_paint
             at eframe-0.22.0/src/native/run.rs:1281:21
  33: eframe::native::run::run_and_return::{{closure}}
             at eframe-0.22.0/src/native/run.rs:152:17
  34: <winit::platform_impl::platform::app_state::EventLoopHandler<T> as winit::platform_impl::platform::app_state::EventHandler>::handle_nonuser_event::{{closure}}
      winit::platform_impl::platform::app_state::EventLoopHandler<T>::with_callback
             at winit-0.28.6/src/platform_impl/macos/app_state.rs:70:13
      <winit::platform_impl::platform::app_state::EventLoopHandler<T> as winit::platform_impl::platform::app_state::EventHandler>::handle_nonuser_event
             at winit-0.28.6/src/platform_impl/macos/app_state.rs:91:9
  35: winit::platform_impl::platform::app_state::Handler::handle_nonuser_event
             at winit-0.28.6/src/platform_impl/macos/app_state.rs:199:21
  36: winit::platform_impl::platform::app_state::AppState::cleared
             at winit-0.28.6/src/platform_impl/macos/app_state.rs:388:13
  37: winit::platform_impl::platform::observer::control_flow_end_handler::{{closure}}
             at winit-0.28.6/src/platform_impl/macos/observer.rs:79:21
      winit::platform_impl::platform::observer::control_flow_handler::{{closure}}
             at winit-0.28.6/src/platform_impl/macos/observer.rs:41:9
      std::panicking::try::do_call
             at std/src/panicking.rs:487:40
      std::panicking::try
             at std/src/panicking.rs:451:19
      std::panic::catch_unwind
             at std/src/panic.rs:140:14
      winit::platform_impl::platform::event_loop::stop_app_on_panic
             at winit-0.28.6/src/platform_impl/macos/event_loop.rs:245:11
      winit::platform_impl::platform::observer::control_flow_handler
             at winit-0.28.6/src/platform_impl/macos/observer.rs:39:5
      winit::platform_impl::platform::observer::control_flow_end_handler
             at winit-0.28.6/src/platform_impl/macos/observer.rs:74:9
  38: <unknown>
  39: <unknown>
  40: <unknown>
  41: <unknown>
  42: <unknown>
  43: <unknown>
  44: <unknown>
  45: <unknown>
  46: <unknown>
  47: <unknown>
  48: winit::platform_impl::platform::event_loop::EventLoop<T>::run_return::{{closure}}
             at winit-0.28.6/src/platform_impl/macos/event_loop.rs:220:22
      objc2::rc::autorelease::autoreleasepool
             at objc2-0.3.0-beta.3.patch-leaks.3/src/rc/autorelease.rs:313:5
      winit::platform_impl::platform::event_loop::EventLoop<T>::run_return
             at winit-0.28.6/src/platform_impl/macos/event_loop.rs:211:25
  49: <winit::event_loop::EventLoop<T> as winit::platform::run_return::EventLoopExtRunReturn>::run_return
             at winit-0.28.6/src/platform/run_return.rs:51:9
      eframe::native::run::run_and_return
             at eframe-0.22.0/src/native/run.rs:132:5
  50: eframe::native::run::wgpu_integration::run_wgpu::{{closure}}
             at eframe-0.22.0/src/native/run.rs:1478:17
      eframe::native::run::with_event_loop::{{closure}}
             at eframe-0.22.0/src/native/run.rs:116:9
      std::thread::local::LocalKey<T>::try_with
             at std/src/thread/local.rs:446:16
      std::thread::local::LocalKey<T>::with
             at std/src/thread/local.rs:422:9
  51: eframe::native::run::with_event_loop
             at eframe-0.22.0/src/native/run.rs:109:5
      eframe::native::run::wgpu_integration::run_wgpu
             at eframe-0.22.0/src/native/run.rs:1475:13