Treemacs extension has a fixed fringe value

[christianramet]

Theme(s)

All themes (base)

What were you expecting?

When I use the treemacs-select-window function back and forth, I expect no fringe modification for the non treemacs windows.

What actually happened?

Using treemacs-select-window twice in a row (selecting the treemacs window then back) actually changes my main windows fringes with no respect to what it was prior to the window selection.

Interpretation:
treemacs-select-window is advised by doom-themes-hide-fringes-maybe which uses a fixed fringe value of 3 with the variable doom-themes-treemacs-bitmap-indicator-width. In my configuration, my fringe is set to a value of 8, and when I call treemacs-select-window twice in a row, the window I come back to sees its fringe being set to 3.

I do not know if a fringe of 3 is a default for Doom Emacs, but the vanilla Emacs experience seems to be 8. Maybe doom-themes-treemacs-bitmap-indicator-width should not be fixed, and take the user fringe size as a default.

A previous comment in another ticket mentions this issue here: #699 (comment)

Steps to reproduce

1. Use a vanilla Emacs (i.e. not Doom Emacs)
2. Make sure your fringe size is different than 3

(setq default-frame-alist
'((menu-bar-lines . 0)
(tool-bar-lines . 0)
(vertical-scroll-bars . nil)
(left-fringe . 8)
(right-fringe . 8)))

4. Call treemacs-select-window twice in a row

Operating system

Fedora 35 and MacOS

Emacs version

27.2 and 28.1

Installed commit of doom-themes

872ea5a