bug#19395: 25.0.50; Setting left fringe to 0 messes up window-width

[Eli Zaretskii <eliz@gnu.org>]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: malsburg@posteo.de,  19395@debbugs.gnu.org
> Date: Wed, 17 Dec 2014 09:16:04 -0500
> 
> >> That sounds wrong: if the user decides to get rid of the left-fringe,
> >> she just shouldn't get any continuation glyph on the left.
> > That's how Emacs worked since v21.1.
> 
> Definitely not 21.1: in 21.1 the fringes could not be modified at all.

But they were the only way to show truncation and continuation
indicators on GUI frames.

> > But then users asked to have continuation and truncation glyphs in
> > that case,
> 
> I do remember users clamoring for the possibility to eliminate the
> fringes, which was indeed added (in the form of set-window-fringes)
> a few versions later (not sure exactly when, but >= 22.1 and <= 22.3).
> 
> I don't remember users asking for "no fringe, but still something where we
> can display the continuation glyphs" (and since the fringe is the thing
> where we display the continuation glyphs, I read this as "no fringe, yet
> with a fringe").
> 
> This said, I wouldn't be surprised if some users asked for that.

  http://debbugs.gnu.org/cgi/bugreport.cgi?bug=11832

> > So what you are suggesting is going back and deleting a feature which
> > was added by users' request.
> 
> Not necessarily: I'm suggesting that maybe the Emacs-22 behavior where
> "continuation glyphs" are only ever displayed in the fringe (and hence
> aren't displayed if there's no fringe) is preferable.

As you can see from the above URL, that was an explicit feature
request, in response to which we provided the feature.  So going back
to Emacs 23 behavior is tantamount to removing the feature.

> Note also that in the OP's situation, there *is* a fringe on the right,
> so I don't see why we need to keep an extra empty space on the right
> since we'll never display a continuation glyph on the right elsewhere
> than in the fringe.

Because of RTL lines.  I explained that in more detail in my other
message.