bug#29889: 27.0.50; Slow visual selection

[Eli Zaretskii]

> From: Sujith <m.sujith@gmail.com>
> Cc: bug-gnu-emacs@gnu.org, 29889@debbugs.gnu.org
> Date: Sat, 06 Jan 2018 06:45:22 +0530
> 
> I have set 'select-active-regions' to 'only' in my .emacs
> to address this issue. Is this the recommended solution for
> this problem ?

That would be my recommendation, yes.  Especially if you happen to
deal frequently with large regions, and you did not disable
transient-mark-mode.

In fact, I cannot understand why the default was changed to t in
7c23dd4.  The discussions leading to those changes all mention the
value 'lazy' (later renamed to 'only') as the default, and there's
nothing I could find explaining why t was eventually deemed a better
default.

Regardless, I still wonder whether region-extract-function should call
buffer-substring-no-properties, at least when it's used to set the
primary selection.  Stefan, any thoughts?