Handle sit-for variants inside timers and process handlers

[lastquestion]

You're "not suppposed to do that", according to the emacs docs, but for example a timer can write a message to the minibuffer via minibuffer-message which calls sit-for internally.

Don't trust anyone, and discount sit-for times inside timers and process handlers, too.

Example repro:

(run-with-timer 1 nil (lambda ()
                        (minibuffer-message "a long message")))

will give

Wed May 27 22:38:11 2020 - 2004 ms - (lambda nil (minibuffer-message a long message)), timer

only because the default wait inside minibuffer-message is 2 seconds.