You can input multiline text in `TextArea` when `multiline=False`

The app:

from prompt_toolkit import Application
from prompt_toolkit.buffer import Buffer
from prompt_toolkit.layout.containers import Window, HSplit
from prompt_toolkit.layout.controls import BufferControl
from prompt_toolkit.layout.layout import Layout

from prompt_toolkit.key_binding import KeyBindings
from prompt_toolkit.widgets import TextArea

kb = KeyBindings()

@kb.add('c-q')
def exit_(event):
  event.app.exit()

buffer1 = Buffer()  # Editable buffer.

root_container = HSplit([
  TextArea(
    prompt='Type something: ',
    multiline=False,
    wrap_lines=False,
    accept_handler=lambda buff: buffer1.insert_text(f"accept_handler called: {buff.text}\n"),
  ),
  Window(height=1, char='-'),
  Window(content=BufferControl(buffer=buffer1)),
])

layout = Layout(root_container)

app = Application(key_bindings=kb, layout=layout, full_screen=True)
app.run()

When multiline=False, pressing enter should trigger accept_handler.

However, when pasting multi-line text to the console, TextArea draws a new line then scroll down. In this case, accept_handler won't be triggered.

Another way to trigger this bug is to type very fast when the computer is slow. I guess it works similarly as copy-pasting.

Windows 10
prompt_toolkit 3.0.47
cmd.exe + Windows Terminal

Start by reproducing the provided TextArea example with multiline=False, especially the paste or rapid-input path on Windows. Trace TextArea and its input handling to determine why a newline is drawn instead of invoking accept_handler; done means multiline input consistently triggers the handler without inserting a new line.