Exception when using .data_view() with cleared table

[pstorozenko]

Hi, discovered some exception thrown when using .data_view() with table that has been recently cleared.

Let me show an example as it clearly demonstrate the issue.

from shiny import App, ui, reactive, render
import pandas as pd

app_ui = ui.page_fluid(
    ui.input_action_button("add_row", "Add row"),
    ui.input_action_button("clear_table", "Clear table"),
    ui.output_text("number_of_selected_rows"),
    ui.output_data_frame("df1"),
)


def server(input):
    df = reactive.Value(pd.DataFrame(columns=["A", "B"]))

    @render.data_frame
    def df1():
        return render.DataGrid(df(), selection_mode="rows")

    @reactive.effect
    @reactive.event(input.add_row)
    def _():
        old_df = df()
        new_df = pd.concat([old_df, pd.DataFrame([[1, 2]], columns=["A", "B"])])
        df.set(new_df)

    @render.text
    def number_of_selected_rows():
        df_selected = df1.data_view(selected=True)
        return f"Selected rows: {len(df_selected)}"

    @reactive.effect
    @reactive.event(input.clear_table)
    def _():
        df.set(pd.DataFrame(columns=["A", "B"]))


app = App(app_ui, server)

When you add a row, click on it and click the clear button you get:

Exception/Error that I got:

Traceback (most recent call last):
  File "/Users/pasza/miniconda3/envs/shiny/lib/python3.12/site-packages/pandas/core/indexing.py", line 1714, in _get_list_axis
    return self.obj._take_with_is_copy(key, axis=axis)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/pasza/miniconda3/envs/shiny/lib/python3.12/site-packages/pandas/core/generic.py", line 4153, in _take_with_is_copy
    result = self.take(indices=indices, axis=axis)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/pasza/miniconda3/envs/shiny/lib/python3.12/site-packages/pandas/core/generic.py", line 4133, in take
    new_data = self._mgr.take(
               ^^^^^^^^^^^^^^^
  File "/Users/pasza/miniconda3/envs/shiny/lib/python3.12/site-packages/pandas/core/internals/managers.py", line 891, in take
    indexer = maybe_convert_indices(indexer, n, verify=verify)
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/pasza/miniconda3/envs/shiny/lib/python3.12/site-packages/pandas/core/indexers/utils.py", line 282, in maybe_convert_indices
    raise IndexError("indices are out-of-bounds")
IndexError: indices are out-of-bounds

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/Users/pasza/miniconda3/envs/shiny/lib/python3.12/site-packages/shiny/session/_session.py", line 1220, in output_obs
    value = await renderer.render()
            ^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/pasza/miniconda3/envs/shiny/lib/python3.12/site-packages/shiny/render/renderer/_renderer.py", line 255, in render
    value = await self.fn()
            ^^^^^^^^^^^^^^^
  File "/Users/pasza/miniconda3/envs/shiny/lib/python3.12/site-packages/shiny/render/renderer/_renderer.py", line 349, in __call__
    return await self._fn()
           ^^^^^^^^^^^^^^^^
  File "/Users/pasza/miniconda3/envs/shiny/lib/python3.12/site-packages/shiny/_utils.py", line 263, in fn_async
    return fn(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^
  File "/Users/pasza/Projects/InnovationLead/playground/app_df.py", line 28, in number_of_selected_rows
    df_selected = df1.data_view(selected=True)
                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/pasza/miniconda3/envs/shiny/lib/python3.12/site-packages/shiny/render/_data_frame.py", line 285, in data_view
    return self._data_view_selected()
           ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/pasza/miniconda3/envs/shiny/lib/python3.12/site-packages/shiny/reactive/_reactives.py", line 283, in __call__
    return _utils.run_coro_sync(self.get_value())
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/pasza/miniconda3/envs/shiny/lib/python3.12/site-packages/shiny/_utils.py", line 378, in run_coro_sync
    coro.send(None)
  File "/Users/pasza/miniconda3/envs/shiny/lib/python3.12/site-packages/shiny/reactive/_reactives.py", line 293, in get_value
    raise self._error[0]
  File "/Users/pasza/miniconda3/envs/shiny/lib/python3.12/site-packages/shiny/reactive/_reactives.py", line 328, in _run_func
    self._value.append(await self._fn())
                       ^^^^^^^^^^^^^^^^
  File "/Users/pasza/miniconda3/envs/shiny/lib/python3.12/site-packages/shiny/_utils.py", line 263, in fn_async
    return fn(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^
  File "/Users/pasza/miniconda3/envs/shiny/lib/python3.12/site-packages/shiny/render/_data_frame.py", line 524, in self__data_view_selected
    return _subset_data_view(selected=True)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/pasza/miniconda3/envs/shiny/lib/python3.12/site-packages/shiny/render/_data_frame.py", line 515, in _subset_data_view
    return data.iloc[data_view_indices]
           ~~~~~~~~~^^^^^^^^^^^^^^^^^^^
  File "/Users/pasza/miniconda3/envs/shiny/lib/python3.12/site-packages/pandas/core/indexing.py", line 1191, in __getitem__
    return self._getitem_axis(maybe_callable, axis=axis)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/pasza/miniconda3/envs/shiny/lib/python3.12/site-packages/pandas/core/indexing.py", line 1743, in _getitem_axis
    return self._get_list_axis(key, axis=axis)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/pasza/miniconda3/envs/shiny/lib/python3.12/site-packages/pandas/core/indexing.py", line 1717, in _get_list_axis
    raise IndexError("positional indexers are out-of-bounds") from err
IndexError: positional indexers are out-of-bounds

I think something's wrong inside shiny, am I right?
Initially, I thought df1.data_view(selected=False) is just None but the error is weird, but it's not the case.