On Fri, Apr 10, 2020 at 4:50 PM Eli Zaretskii <eliz@gnu.org> wrote:
> From: João Távora <joaotavora@gmail.com>
> Date: Fri, 10 Apr 2020 15:38:58 +0100
> Cc: nadiasggeb001@gmail.com, 40529@debbugs.gnu.org
>
>  Exactly.  I think this answers your question in the first paragraph.
>
> Yes, and it raises another one for which I don't have an answer to. 
> Why does it do that? What do line numbers have to do with
> tabulated lists?

When line numbers are turned on or off in a buffer under
tabulated-list-mode, the buffer needs to be redisplayed because the
column counts change, and that affects alignment of the columns.
That's why tabulated-list-mode defines a function to be run from
display-line-numbers-mode-hook.

Thanks.  That makes some sense, though I didn't know line numbers
affected column counts in the actual buffer contents (I though they used
the margin or the fringe, but I confess my ignorance here).  Anyway, this
leaves me wondering if there isn't a hook ordering bug here. Maybe it's
just a question of delaying entry in tabulated-list-mode until important stuff
is set up.  I don't know, I haven't looked at actual code yet.

João