RE: Advice on troubleshooting function to "unscroll"

[Drew Adams]

> why did scroll-up-command work where the still useful but not
> appropriate scroll-up did not?

That was already answered, and I thought that you understood
the answer.  The problem was that the code checked whether the
current command was `scroll-up', and it of course never would
be.  `scroll-up' is called by `scroll-up-command', but only the
latter, never the former, is invoked by you interactively, i.e.,
as a command.  Variables `this-command' and `last-command' are
only set to functions when they are invoked as commands.

> And if I'm being honest about why I did not go to Edebug it's because I
> was anticipating great difficulty reading the backtrace statements.  I
> thought my problem might be compounded by a more general illiteracy in
> that regard...

The Emacs manual sends you to the Elisp manual, node `Edebug',
for information about using that debugger.  That section of the
Elisp manual is like a mini-manual about Edebug.

Why it does not send you instead to the Elisp manual node
`Debugger' (which has title "The Lisp Debugger"), I don't know.
That node covers the regular debugger (i.e., `debug').

`debug' is older than `edebug'.  Perhaps the person who wrote
`edebug' decided to send readers of the Emacs manual to learn
about Edebug. ;-)

(In older versions of Emacs, e.g. Emacs 20, there was no link
from the Emacs manual to the Elisp manual for either the regular
Lisp debugger or Edebug, but there were multiple mentions of
using the former - and only no mention of Edebug, except to say
that edebug.el was contributed by Daniel LaLiberte.)