bug#39649: 27.0.60; tab-line doesn't scroll

[João Guerra]

It does have your patch, but just the latest one in this thread.
Video demonstration: https://youtu.be/xq_JMBO4SyI.
I'm using Emacs from
https://alpha.gnu.org/gnu/emacs/pretest/windows/emacs-27/. It does
have XPM support.

Issue still happens when I do
(setq tab-line-left-button nil)
(setq tab-line-right-button nil)

On Tue, 25 Feb 2020 at 22:33, Juri Linkov <juri@linkov.net> wrote:
>
> Please help to understand how to reproduce this bug:
>
> > I have the same issue with `emacs -q`
>
> Have you tried `emacs -Q`?
> I don't know if there is any difference between
> `emacs -Q` and `emacs -q` on Windows.  But `emacs -q`
> loads all resources so maybe it loads additional
> face definitions for tab-line.
>
> I see that left/right arrows in your bug report are XPM images.
> But I don't understand how this is possible because
> (info "(efaq-w32) Image support") says that Emacs has
> no built-in support for XPM on Windows.
>
> Please try to reproduce the same bug without XPM images
> by evaluating these lines:
>
> (setq tab-line-left-button " <")
> (setq tab-line-right-button "> ")
>
> Also it's possible that maybe the widths of these buttons
> affect the calculations somehow.
>
> Please also try to remove these arrow buttons temporarily with:
>
> (setq tab-line-left-button nil)
> (setq tab-line-right-button nil)
>
> Do you see the same bug?
>
> > on GNU Emacs 27.0.60 (build 1, x86_64-w64-mingw32) of 2020-02-10.
>
> The compilation date is 2020-02-10.
> Did you apply the patch that I sent?
> I could commit the patch, then you could
> update your repository if you want.