Hi! I have some rules in my display-buffer-alist that inspect buffer properties such as major-mode. When my rules weren't correctly catching the vterm buffer on initial creation, but were catching it on subsequent displays, I looked into the reason why.

I doubt other people have a similar issue, and it's easy enough for me to work around it. But here's hoping that this change is small enough that "consistency with other Emacs libraries" is sufficient reason to accept it.

This makes sense to me. Would you be able to point me to the equivalent code for some of the other modes you mentioned?

Sorry for the delayed response here. I've linked to the relevant lines (in emacs 29.4) for the other modes below:

• term
  • set mode: https://github.com/emacs-mirror/emacs/blob/emacs-29.4/lisp/term.el#L1590
  • display buffer: https://github.com/emacs-mirror/emacs/blob/emacs-29.4/lisp/term.el#L1591
• ansi-term
  • set mode: https://github.com/emacs-mirror/emacs/blob/emacs-29.4/lisp/term.el#L4413
  • switch to buffer: https://github.com/emacs-mirror/emacs/blob/emacs-29.4/lisp/term.el#L4427
• ielm
  • set mode: https://github.com/emacs-mirror/emacs/blob/emacs-29.4/lisp/ielm.el#L650
  • display buffer: https://github.com/emacs-mirror/emacs/blob/emacs-29.4/lisp/ielm.el#L651
• SQLi
  • set mode: https://github.com/emacs-mirror/emacs/blob/emacs-29.4/lisp/progmodes/sql.el#L4618
  • display buffer: https://github.com/emacs-mirror/emacs/blob/emacs-29.4/lisp/progmodes/sql.el#L4655
• inferior Python
  • set mode: https://github.com/emacs-mirror/emacs/blob/emacs-29.4/lisp/progmodes/python.el#L3590
  • display buffer: https://github.com/emacs-mirror/emacs/blob/emacs-29.4/lisp/progmodes/python.el#L3593

Hi! I have some rules in my display-buffer-alist that inspect buffer properties such as major-mode. When my rules weren't correctly catching the vterm buffer on initial creation, but were catching it on subsequent displays, I looked into the reason why.

I doubt other people have a similar issue, and it's easy enough for me to work around it. But here's hoping that this change is small enough that "consistency with other Emacs libraries" is sufficient reason to accept it.

I would help to add this explanation to the commit for anyone reviewing the commit history.

@Thaodan done.