Juri Linkov <juri@linkov.net> writes:

>> I'm not sure I understand why they need to be installed on emacs-30.
>> Is this a regression in Emacs 29 or Emacs 30?  What bad things will
>> happen if we install the changes on master instead>

No regression.

> Replacing hard-coded logic with customizable variable
> for external packages like activities.el is needed
> as soon as possible on emacs-30 because hard-coded logic
> hinders the use of packages.
>
> However, there is no hurry to change the default behavior
> to match a symbol name instead of checking face names.
> Therefore I think better to move the existing code
>
>   (memq (get-text-property 0 'face (nth 2 item)) tab-bar-auto-width-faces)
>
> to the new predicate function on emacs-30.  Then activities.el
> can change it to another function that matches a symbol.
>
> Then on master the default body on the new predicate
> could be replaced from checking the face to match a symbol.
> Also changes in tab-bar--format-tab-group should be on master as well.

Much as I'd like to use these changes asap, I think this patchset should
go entirely on master.  I see these changes as adding functionality
(making tab-bar tabs more extensible) rather than bug fixes.

>>> Does this change warrant a NEWS entry?
>>
>> Yes, since you are adding a hook variable.  Obsolescence of a variable
>> also requires a NEWS entry.

Please see attached patches.

Thanks!

Joseph