bug#16028: 24.3.50; Latest build completely breaks my thumnail frames code

[Drew Adams]

> Put in some sit-fors.  Check whether and which exception handlers get
> called.  Check which frame parameters get set and reset.

OK, I found that adding a (sit-for 0) after this call in
`thumfr-thumbify-frame' fixes the problem:

  (enlarge-font (- thumfr-font-difference) frame)

(And no error handlers were called with this simple test.)

Do I need to do that in my code, or will you be doing something to
your fix that incorporates this?

If I need to do it, should I add the sit-for to the end of `enlarge-font'
or add it only after the above call in `thumfr-thumbify-frame'.

IOW, is this something that needs to be fixed in the frame
shrinking/enlarging code, even though I do not generally notice a problem
with that, or should it be handled only here and there, where I happen to
notice a problem.  (Normally, I would probably opt for the latter, but if
you think this is now a wise or necessary thing to do in general, then
let me know.)

Thx.