bug#62816: 30.0.50; ElDoc blinks echo area when eldoc-documentation-compose is used

[Dmitry Gutov <dmitry@gutov.dev>]

On 14/04/2023 03:22, Dmitry Gutov wrote:
>>>> Another option is just to temporarily disable eldoc during the duration
>>>> of the Company completion session.
>>>
>>> Right.
>>>
>>> And yet another solution would be to detect that Eldoc will be used,
>>> and try to plug into its documentation functions to display the meta
>>> thingy alongside the other info.
>>>
>>> That's at least 3 potential solutions now.
>>
>> I think you should do the "bookkeeping" one, at least a very simple
>> version.  Just record in your concept of a "company session" if there
>> was ever a non-nil :company-docsig sent from anywhere that required
>> echoing.  Until there is, never clear on nil :company-docsig.
>> Eventually, if there is something to echo, tough luck: display it and
>> proceed as currently, clearing always on nil, risking flickering.
>> Suspect this should fix 95% of the cases, certainly Eglot usages.
> 
> Yeah, that should be the most conservative solution. Maybe I'll start 
> with it.

I've pushed a halfway-there solution which still seems to satisfy both 
main scenarios (exemplified by Elisp and Eglot), so that seems addressed.