bug#32839: 27.0.50; recenter doesn't redisplay

[Eli Zaretskii <eliz@gnu.org>]

> From: Juri Linkov <juri@linkov.net>
> Cc: 32839@debbugs.gnu.org
> Date: Sun, 30 Sep 2018 22:40:18 +0300
> 
> > I don't think I agree.  The current name reflects what that argument
> > causes, you just interpret "redisplay" to mean "redraw the frame",
> > which is not an accurate interpretation, since the display engine has
> > its own logic to decide what exactly needs to be redrawn at any
> > particular moment.
> 
> When an argument name is a verb in the imperative mood, this means only
> one thing: it should do what it claims it will do.

And it does: it redisplays the current window.  It does _not_ always
redisplay other windows, and does _not_ redraw the entire frame unless
another argument tells it to do so.

IOW, "redisplay" is not the same as "redraw the frame".  If the
argument's name were "redraw-frame", then I'd agree with you that the
name is misleading.

> > Renaming the argument as you propose would be a step backwards, since
> > it describes the _purpose_ (as opposed to _effect_) of that argument,
> > and that could easily change with further development, and is not
> > accurate even with the current code.
> 
> Other commands that use the argument name 'interactive' have the same
> assumption of describing the purpose, not effect.

It is possible that in other cases that name is the best one we found;
or it could be that some of those arguments need to be renamed to
something else.  The decision is on a per-case basis, and cannot be
global.