bug#56874: 28.1.50; tab-bar-format-align-right should probably use string-width

[Adam Porter]

Hi Juri,

On 8/1/22 13:13, Juri Linkov wrote:

> Please check Emacs 29 where tab-bar-format-align-right
> contains a better improvement:
>
>    (string-pixel-width (propertize rest 'face 'tab-bar))
>
> Does this work in your case as well?

I don't have an Emacs 29 build readily accessible, but I see that Emacs 
28 has the function `shr-string-pixel-width', which I'm guessing is 
similar.  So I tried using that function, and it is an improvement, but 
not quite correct: rather than wrapping onto a new line, the string 
appears on the same line as the rest of the tab-bar, but it is not 
right-aligned as it should be.

If it would help you reproduce the problem to test whether Emacs 29 
already has a fix, all that seems to be necessary is to set the tab-bar 
face to, e.g. ":height 1.2", and add a string of some length (e.g. about 
20) to the global-mode-string, and see whether it wraps onto a new line 
and whether it's right-aligned.  If it seems correct on Emacs 29, then 
I'd guess it's already solved.

Thanks,
Adam