AttributeError: 'NoneType' object has no attribute 'viewport'

[wookayin]

Neovim version: NVIM v0.6.0-dev+1556-gc642f3ac2, but it happens in v0.5.0 release as well

error caught in async handler '.../vim/plugged/semshi/rplugin/python3/semshi:function:SemshiVimResized [[71, 102]]'
Traceback (most recent call last):
  File ".../vim/plugged/semshi/rplugin/python3/semshi/plugin.py", line 91, in event_vim_resized
    self._update_viewport(*args)
  File ".../vim/plugged/semshi/rplugin/python3/semshi/plugin.py", line 231, in _update_viewport
    self._cur_handler.viewport(start, stop)
AttributeError: 'NoneType' object has no attribute 'viewport'

Often semshi throws an error when vim gets resized. It might be a conflict with other plugins installed, but it sometimes happens. No idea why self._cur_handler is not ever set.

[wookayin]

This can be fixed like wookayin@11cf4e7