bug#12463: 24.2; pos-visible-in-window-p gets slower over time

[Eli Zaretskii]

> From: Stefan Monnier <monnier@IRO.UMontreal.CA>
> Cc: lekktu@gmail.com, cyd@gnu.org, jwalt@garni.ch, 12463@debbugs.gnu.org
> Date: Fri, 21 Sep 2012 16:34:41 -0400
> 
> >> Sorry, can't remember.  Probably because I generally prefer passing
> >> arguments explicitly over passing them via dynamic binding.
> > We have gobs of functions in Emacs that access global variables like
> > Vdynamic_library_alist.  I don't think one more function will change
> > anything.
> 
> The question is not "global or not" but "let-bound or not".
> If it's generally accessed as a global var, that's perfectly fine.
> If it's generally let-bound, I prefer an explicit argument.

Sorry, I don't follow.  We are discussing C code, so how do you mean
"let-bound"?  If you mean by using specbind, then no, it isn't
let-bound, it's a global variable that always has the same value as it
had when the last cons cell was added to it.