bug#65217: 29.1; set-frame-size gets confused and drops calls

[Gregory Heytings]

> > Instead of assuming that Elisp programmers understand these subtle 
> > points, can't we provide an optional argument to set-frame-size, say 
> > FORCE, that would do that sit-for?
>
> What would you pass to
>
>  (modify-frame-parameters my/frame `((width . ,width) (height . ,height)))
>
> in my/twiddle?

I'm not sure yet, but after thinking a bit more about this, ATM my 
conclusion is that adding a sentence in the docstings of set-frame-* and 
modify-frame-parameters, suggesting to use (redisplay t) after these 
functions, would be enough.