[mu4e bug] Headers line of headers view appears in wrong window in a different frame

[nuthub]

Describe the bug

When headers view is refreshed by some event while in another window in another frame, the headers line is removed from the headers view and added to the other window in another frame. The other window does not show any mu4e related buffer. The effect didn't occur some weeks ago.

How to Reproduce

That's the difficult part, I didn't succeed to reproduce and I first wanted to know, whether this is a known effect. If it is not a known effect, I further try to narrow down a way to reproduce.

Environment

GNU Emacs 30.2 with mu 1.12.14 on a Guix system. I have frames-only-mode enabled in emacs.

Checklist

• you are running either an 1.10.x/1.12.x release or master (otherwise please upgrade)
• you can reproduce the problem without 3rd party extensions (including Doom/Evil, various extensions etc.)
  • I will try to do this, when I know, it's not something already known
• you have read all of the above

Screenshots:

1. headers view without headers line
2. some mu4e unrelated buffer (org roam daily capture buffer) showing the headers line

[djcb]

This sounds somewhat similar-ish to #2766.

My emacs does not have frames-only-mode. What is it?

[nuthub]

Ok. At least it seems that it may be somehow related to #2766, but it's not exactly the same.

frames-only-mode opens new emacs windows in new frames. This is useful to let a tiling window manager manage emacs's windows. However, I just deactivated this minor mode and the issue occurs also without frames-only-mode.

As I know that this is not a well known issue now, I know that I should investigate further the circumstances. I will deactivate other minor modes as well or start with a more vanilla emacs config to narrow down the cause and report back, when I know more.

[averter]

Same issue occurring in my org-mode buffer, although

1. I'm not using frames-only-mode
2. The headers line doesn't disappear out of my headers view; it is simply replicated into the org-mode buffer.

Reopening/refreshing the org-mode file removes the spurious headers line.

Environment

GNU Emacs 30.2 with mu 1.12.14 on a linux mint system.

[nuthub]

I further tested and can exclude the following roots of cause:

• frames-only-mode
• spacious-padding (no idea, why I suspected it)
• emacs daemon / server mode
• mu4e-modeline-mode
• org mode: I also had my *scratch* buffer with headers line:

[djcb]

Was able to reproduce; it's fairly easy: open two emacs frames, one with mu4e running (say, looking at your inbox folder); then in the other frame, run M-x shell, cp some message file from some different maildir to the inbox and run M-x mu4e-update-index (while still focus is on the shell frame).

Problem seems to be some misplaced ')'. I've pushed an update, can you confirm this fixes the header-line problem?

[nuthub]

Was able to reproduce; it's fairly easy: open two emacs frames, one with mu4e running (say, looking at your inbox folder); then in the other frame, run M-x shell, cp some message file from some different maildir to the inbox and run M-x mu4e-update-index (while still focus is on the shell frame).

yes, that's a reliable way to reproduce. Strange that this wasn't reported earlier, I feel it's a rather common workflow. In my setup, I use goimapnotify that triggers (mbsync +) emacsclient -e '(mu4e-update-index)' on new mails.

Problem seems to be some misplaced ')'. I've pushed an update, can you confirm this fixes the header-line problem?

I confirm that the issue seems to be solved on my GNU Guix system with mu/mu4e built from 7dc8216 (showing up as 1.12.15-pre1).

[djcb]

Thanks, @nuthub! Closing this.