Source of potential bug in gptel?

[EyoelYT]

Related: karthink/gptel#909

Description of the bug
While using evil-mode, the region shown in the footer of the gptel-menu transient changes as soon as you press the first key inside the transient. My question is: could this be a bug from transient in any way?

Steps to reproduce

1. Start Emacs with evil-mode enabled.
2. Have an active region in the current buffer using evil's M-x evil-visual-line
3. Open gptel menu with M-x gptel-menu
4. Press any key (e.g. n, p, <tab>, arrow keys, etc.) within the transient.
5. Observe that the footer’s region display updates or resets on that first keypress to show a different region.

Expected behavior
The region shown should remain exactly as it was when the menu opened.

Actual behavior
On the first keypress within the transient, the footer’s region info changes.

Environment

• Emacs: 30.1
• Transient: 0.9.2
• Evil: 1.15.0
• gptel: latest master branch at time of testing

[tarsius]

Like the maintainer of gptel, I do not use evil. Additionally I do not use gptel. evil makes Emacs unusable for me, so I cannot experiment. And I am preoccupied with other things.

I've had a look at the code and I haven't spotted anything that would explain the behavior you observe.

I recommend you use debug statements to check whether we are in the expected buffer (i.e., not the menu buffer but the buffer whose text is expected to be used). Note how Transient uses transient-with-shadowed-buffer to make that temporarily current while calling :description functions. Maybe evil somehow makes some other buffer temporarily current (which would potentially be a big problem).

[tarsius]

The discussion at karthink/gptel#909 has progressed further.

All I can add is that I don't even understand what evil-visual... is supposed to do. Is it a re-implementation of "the region" (which isn't quite compatible and/or has to be synced with that)?

[EyoelYT]

I think so. Based on some of my experiments, it seems to be a re-implementation of regional selection to emulate Vim's visual selection behavior, as it is different from Emacs's' implementation (e.g. cursor position, etc). I plan to discuss it with the evil maintainers.