bug#33959: 26.1.90; python.el font-lock buffer wreaks havoc when company is enabled

[Noam Postavsky]

Noam Postavsky <npostavs@gmail.com> writes:

> Noam Postavsky <npostavs@gmail.com> writes:
>
>> Carlos Pita <carlosjosepita@gmail.com> writes:
>>
>>> I'm unable to get your output, here the font lock buffer always
>>> contains one line.
>>
>> Hmm, it might have to do with the fact that I'm running ipython over
>> TRAMP, since my main box doesn't have IPython 6.x.  But I suspect that
>> only affects the timing, so that it's still theoretically possible
>> (although less likely) for it to happen when running locally.
>
> I installed IPython 6.5.0 locally using pip, and I still see the same
> behaviour (including repeated input prompt numbers).

I think I figured out what the difference is: I forgot to add
--simple-prompt to python-shell-interpreter-args.  After doing that,
your patch does indeed fix the problem.  I'd still like a deterministic
test, though, since this bug is such a pain to reproduce.