bug#34763: 27.0.50; url-retrieve-synchronously misbehaves inside eldoc-documentation-function

[Dmitry Gutov <dgutov@yandex.ru>]

Can anybody reproduce this?

On 05.03.2019 23:34, Dmitry Gutov wrote:
> 1. Evaluate the attached .el file.
> 
> 2. Start typing, randomly and with certain pauses, trying to align the
> interval to the "Contacting host" messages.
> 
> At first, Emacs is responsive, and the requests are duly aborted, like
> 'while-no-input' obliges them to. A little bit later (maybe 10-30
> seconds later), I see errors like "Transfer interrupted", and Emacs
> stutters when that happens. Later on, any HTTP request to the same host
> freezes Emacs until I press C-g. The attached screenshot shows the
> messages log and the list of processes at the end.
> 
> I guessing this became much easier to trigger with
> 12e922156c86a26fa4bb2cb9e7d2b3fd639e4707 when eldoc started using
> when-no-input. But whatever underlying problem is there in url-http,
> it's probably been there longer.
> 
> In GNU Emacs 27.0.50 (build 20, x86_64-pc-linux-gnu, GTK+ Version 3.22.30)
>   of 2019-03-05 built on zappa
> Repository revision: 9b93e3b0759d562989283eaecf32e075f984c18c
> Repository branch: master
> Windowing system distributor 'The X.Org Foundation', version 11.0.12001000
> System Description: Ubuntu 18.04.2 LTS