Re: tab-bar-switch-to-tab removes custom tab data?

[Juri Linkov]

> I'm not sure if this is intended, or if what I'm doing is allowed, but I
> noticed that after I add an association to the current tab and then use
> tab-switch twice, to change tab and then change back, the association I
> added is gone.

So you want to add more metadata to a tab?
Once in the past I proposed such a feature,
but no one needed it :)  Now this could be added.

> Here's the function I'm using to add the association:
>
>   (defun burly-tab--windows-set-after-advice (&rest _ignore)
>     "Set current tab's `burly-bookmark-name' to BOOKMARK-NAME.
>   To be used as advice to `burly--windows-set'."
>     (tab-rename burly-opened-bookmark-name)
>     (let ((current-tab (tab-bar--current-tab-find)))
>       (setf (alist-get 'burly-bookmark-name (cdr current-tab))
>             burly-opened-bookmark-name)))
>
> After that function is run, this:
>
>   (tab-bar--current-tab-find)
>
> Evaluates to:
>
>   (current-tab
>    (burly-bookmark-name .
>     #("Burly: Burly.el" 0 15
>       (face nil)))
>    (name .
>     #("Burly: Burly.el" 0 15
>       (face nil)))
>    (explicit-name . t))
>
> Then after switching tabs and back, it evaluates to:
>
>   (current-tab
>    (name .
>     #("Burly: Burly.el" 0 15
>       (face nil)))
>    (explicit-name . t))
>
> I assumed that, since the tab is an alist, I could add my own data to
> it, but maybe this is not intended.  If not, could it become so?  :)  I
> could work around it by using the tab's name, but that would be less
> flexible and robust.  I'd also like to store other data to tabs in the
> future, and that wouldn't work as well with relying on the tab name.

I completely agree, this should be supported asap.