Re: as the accident occued... long lines in emacs buffers.

[Eli Zaretskii]

> From: David Kastrup <address@hidden>
> Date: Fri, 13 Nov 2015 17:40:02 +0100
> Cc: John Wiegley <address@hidden>, Brandon Invergo <address@hidden>,
>       address@hidden
> 
> > I'll settle for "as fast as one would expect given its behavior on short
> > lines".
> 
> Though purportedly this should have been somewhat addressed by
> 
> cache-long-scans is a variable defined in ‘C source code’.
> Its value is t

No, this variable is unrelated.  It only helps when Emacs looks for a
newline.  By contrast, redisplay slowness with long lines has almost
nothing to do with searching a buffer for newlines, its main cause is
that to move to the next visual line the display engine must
completely traverse the current line.