bug#42254: 27.0.91; display-line-numbers-mode incoherent shifting behaviour

[Fernando Peña]

Sorry for the Reply All, it's my first time mailing over here.

I tested it on different computers and it always happens.

These are the step to reproduce it:

1. Open emacs with emacs -q
2. Open an empty buffer
3. M-x display-line-numbers-mode
4. Insert 95 lines (C-u 95 RET)

You should see that there's an extra space on the left of the line numbers, and

when you scroll up until line 90 or 85 (I think it depends on the window size)

it disappears. If you scroll down again to the bottom, the buffer is again

shifted to the right.

El mié., 8 jul. 2020 a las 16:50, Eli Zaretskii (<eliz@gnu.org>) escribió:

[Please use Reply All to reply, so that the bug tracker gets CC'ed.]

> From: Fernando Peña <ferpb1999@gmail.com>
> Date: Wed, 8 Jul 2020 16:38:57 +0200
>
> Okay, thanks very much for your time. Yeah, I tweaked all the variables I saw in the mode, including the one
> you mentioned. The problem is that when the buffer has 80-99 lines for example, it still shifts to the right
> when displaying the bottom.

If the variable I mentioned is non-nil, there shouldn't be any shift
at all.  Can you show an example of such a file?  Maybe there's some
bug after all.