bug#49806: 28.0.50; tab-bar-format with global mode string doesn't always remove global-mode-string

[Juri Linkov]

tags 49806 fixed
close 49806 28.0.50
thanks

> In GNU Emacs 28.0.50 (build 3, x86_64-pc-linux-gnu, X toolkit, cairo version 
> 1.16.0, Xaw scroll bars)
>  of 2021-07-27 built on icterid
> Repository revision: fb27708f51fb0fd60cd00cd8ea7bfc9248eb0040
> Repository branch: feature/rcirc-update

Maybe your branch is not updated to the recent master?
We fixed this a week ago.  But it would be nice
to find such solution that would avoid the need
to update tab-bar--define-keys manually every time
when the default value of mode-line-misc-info changes:

> When I change this to
>
>         (member '(global-mode-string ("" global-mode-string))
>                                  mode-line-misc-info)
>
> reflecting the default value of mode-line-misc-info, it works. 
>
> I am uncertain if this is intentional, or if even 
>
>         (assq 'global-mode-string mode-line-misc-info)
>
> would do the job.

The intention was to check if mode-line-misc-info contains
the default value of 'global-mode-string', and update
only the default value.  But (assq 'global-mode-string mode-line-misc-info)
will be called every time, even when the value was already changed.