Could/should Doom remove margin from eglot-code-action-indications?

[marienz]

I confirm that...

• I searched the FAQ, issue tracker, discussions board, documentation, and wiki, and found nothing about my issue.

• I read the debugging guide and researched the issue to the best of my ability.

• My issue can be observed on the latest available commit of Doom.

• My issue can be observed on a stable release of Emacs (i.e. doesn't end in .50, .60, or .9*)

Describe your issue

(A different way of phrasing this question might be "are there obvious circumstances or customizations that result in left-margin-width being non-zero in eglot-managed buffers"...)

The default value of eglot-code-action-indications is (eldoc-hint margin), in which "margin" means (according to eglot's documentation) "A special indicator appears in the margin".

By default, this seems to have no effect, because the margin is not displayed (left-margin-width remains zero). But with a default font that does not contain special characters like the one eglot uses for this indicator and/or the lightning bolt character here (I didn't check which of the two triggers it) and a fallback font that is taller, there is an annoying side effect: the additional height that would be required to display that character affects the line point is in. This means that when moving point somewhere a code action is available, after eldoc-idle-delay that line becomes slightly taller, shifting everything below it down. This is rather distracting when moving point around. See screen capture, particularly the lines with getNixpkgs below point shifting up and down slightly as point moves.

Setting eglot-code-action-indications to just (eldoc-hint) fixes it, with no negative effects as long as the margin is not displayed (left-margin-width remains 0).

Would that be a reasonable thing for Doom to do, or would that annoy users for whom the margin is displayed (which I'm not sure how to trigger short of manually setting left-margin-width)?

(Happy to send a PR but if "non-zero left margin" is a more common configuration than "small bitmap font for doom-font" my change would make things worse...)

Steps to reproduce

Enable :tools (lsp +eglot) and one or more languages with code actions (my demo uses (nix +lsp) but Rust works too, and probably most languages do).

The font in my demo is (setq! doom-font (font-spec :family "Terminus" :size 18 :weight 'normal)).

System information

https://github.com/user-attachments/files/22438641/doom-info.txt

[hlissner]

As of doomemacs/doomemacs@d6e1f25, I've removed margin from eglot-code-action-indications. I think the eldoc hint is enough, but it also seems to catch beginners by surprise when their font doesn't support emoji and it ends up increasing the line's height. Anyhow, I'll keep an eye on this in case there are other side effects.