bug#31666: Bad interaction between visual-line-mode and wrap-prefix on long lines

[Eli Zaretskii]

> From: Stephen Berman <stephen.berman@gmx.net>
> Cc: npostavs@gmail.com,  clement.pitclaudel@live.com,  31666@debbugs.gnu.org
> Date: Fri, 01 Jun 2018 10:00:52 +0200
> 
> > It will also have a nasty (IMO) effect, whereby adding or removing a
> > character to the "bbb..." part will make the display change between
> > this:
> >
> >    aaaaaaaaaaaaaaaa
> >    bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
> >
> > and this:
> >
> >    aaaaaaaaaaaaaaaa bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
> >
> > This will cause all the rest of the text below this line to scroll up
> > or down, 
> 
> But this is what already happens with visual-line-mode enabled...
> 
> >          which will require us to disable several redisplay
> > optimizations when just one character is inserted/deleted.
> 
> ...or have I misunderstood what you're referring to?

Currently, it happens only when a line becomes continued from
non-continued.  With the above proposal, it will happen even when the
line already was continued.

> > The usual way of handling these situations is to turn on
> > truncate-lines.  Any reasons why you don't do that in that mode?
> > Especially since we now have horizontal scrolling of just the current
> > line?
> 
> I would find it more inconvenient to scroll to see the whole item.

Emacs hsrcolls automatically, as you no doubt know.

Anyway, that was only a suggestion.