bug#27743: 26.0.50; Native Line Numbers seem to reset Tab Width

[Frank Terbeck <ft@bewatermyfriend.org>]

At work we're using a tab-width of 4 (yeah, I know). I tried the new
native line number code with that and saw that the tab-width reverted to
eight characters. As soon as you disable line number display, tab-width
is back to whatever it is actually configured to.

This can in fact be reproduced from "emacs -Q". Just open a file that
uses tabs for indentation. Then set tabulator width:

  (setq tab-width 4)

The display of the tabulator width should now visibly be four
characters. Now enable line number display:

  (setq display-line-numbers 'relative)

Now the tabulator display returns to eight characters. This is the bug
that I'm reporting. Disabling line number display:

  (setq display-line-numbers nil)

...returns the tabulator width to four characters.


Regards, Frank


In GNU Emacs 26.0.50 (build 3, x86_64-pc-linux-gnu, GTK+ Version 3.22.16)
 of 2017-07-15 built on spock
Repository revision: 89c5d59280edaf89b959597a39d848b54c36975a
Windowing system distributor 'The X.Org Foundation', version 11.0.11903000
System Description:	Debian GNU/Linux unstable (sid)

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
irtt.c has auto save data; consider M-x recover-this-file
Making completion list... [3 times]
4 (#o4, #x4, ?\C-d)
Making completion list...
relative
user-error: Beginning of history; no preceding item

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Memory information:
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