Re: Text Properties And Buffer Modification

[Eli Zaretskii]

> From: Stefan Monnier <address@hidden>
> Cc: address@hidden
> Date: Wed, 05 Dec 2018 15:54:08 -0500
> 
> >> > Don't forget that the modified status is important for more than
> >> > just saving to a file: it is important for redisplaying the
> >> > buffer, for example.
> >> Really?
> > Is that a rhetorical question?
> 
> Not at all.  I know that set-buffer-modified-p has historically been
> linked to force-mode-line-update, but other than that I had no idea that
> the ticks would affect redisplay in any significant way (beside the
> obvious stars in the mode-line, obviously).
> 
> I'm still not clear why either.

See my response to Martin.  Some redisplay optimizations need to know
the reason why a buffer should be redisplayed, so they look at the
buffer's modification tick count (and on a similar count for
overlays).  Maybe that's not "significant" for you, but IMO redisplay
optimizations are very important, and disabling them could sometimes
mean severe degradation in responsiveness.