bug#71223: 30.0.50; stack overflow after very fast opening and closing of frames

[Stefan Monnier]

> Alternatively, we could add a method of waiting without calling
> wait_reading_process_output.  E.g., an additional argument to
> sleep-for.  WDYT?

If at all possible, I'd rather not wait (register a callback instead).
As a general rule `sit-for` is a source of problems in ELisp code.


        Stefan