bug#29597: 26.0.90; line-number-display-width returns incorrect width

[Eli Zaretskii]

> From: Paul Rankin <hello@paulwrankin.com>
> Cc: eliz@gnu.org
> Date: Fri, 08 Dec 2017 11:44:06 +1000
> 
> I had a look in the source of display-line-numbers.el in the repo but cannot 
> find the definition of line-number-display-width.
> 
> But this is irrelevant, the line number width is clearly 4 characters, lining 
> up with File in the menu bar.
> 
> (string-width "File")
> 4
> 
> It clearly fails to count to four. Adding a docstring that 2 really equals 4 
> is absurd.

Like I said, it behaves as designed: returns the number of digits used
to display the line number.  (The source is in indent.c.)  If you need
something different for your needs, the function can provide 2 other
related values, controlled by the optional; variable.

All of that is in the doc string on the release branch, and also in
the ELisp manual.

> Please don’t close bugs until they’re actually closed.

I didn't close this bug, so I'm not sure why you are asking to do
something that we always don anyway.