Re: Distinguishing: Temporary v. Semi-Permanent -- Horizontal Scrolling

[Keith David Bershatsky]

Thank you, Eli.  If we complicate the examples by assuming that the 
buffer-local variable auto-hscroll-mode is set to 'current-line for both case 3 
and case 4, then an additional test would be needed when moving IT over the 
current line.  How do we know that the middle line in case 4 ("deserves 
fudge.") is horizontally scrolled differently than the lines above and below?

Every good boy deserves fudge.
Every good boy deserves fudge.
Every good boy deserves fudge.

3.  Semi-permanent Horizontal Scrolling:  (scroll-left 6 t)
    (setq-local auto-hscroll-mode 'current-line)

good boy deserves->
good boy deserves->
good boy deserves->

4.  Semi-permanent Horizontal Scrolling:  (scroll-left 6 t)
    (setq-local auto-hscroll-mode 'current-line)

good boy deserves->
deserves fudge.
good boy deserves->

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DATE:  [07-03-2018 12:29:55] <03 Jul 2018 22:29:55 +0300>
FROM:  Eli Zaretskii <address@hidden>
> 
> > Date:  Mon, 02 Jul 2018 19:44:36 -0700
> > From:  Keith David Bershatsky <address@hidden>
> > Cc:  address@hidden
> >
> > Q:  In addition to (it->w->min_hscroll > 0), what test will help us 
> > distinguish between the 3rd and 4th situations above?
> 
> In case 4 this condition should be true:
> 
>   EQ (Fbuffer_local_value (Qauto_hscroll_mode, buf), Qcurrent_line)