Re: hscroll-step doc bug; cannot turn off hscroll by binding

[Richard Stallman]

        Hscrolling is done by the redisplay engine _after_ the command has
        completed, so any temporary change to hscroll related variables will
        have no effect on how things are displayed.

    Too bad. How about explaining this in the manual or doc string?

It follows from a basic understanding of the architecture of Emacs.
All variables that control redisplay take effect only at the time of
redisplay, so the values that matter are the values in effect at the
time of redisplay.

I will edit display.texi to talk about this.