Subject: bug#38111: 27.0.50; globalized-minor-mode not enabled on get-buffer-create

From: Eli Zaretskii <[email-masked]>
Date: Fri, 08 Nov 2019 11:50:03 +0200

> From: Juri Linkov <[email-masked]>
> Date: Thu, 07 Nov 2019 23:53:04 +0200
> 
> This looks like a bug.  I found this issue while using global-tab-line-mode,
> but to confirm that it's unrelated to tab-line, this bug report uses another
> globalized minor-mode global-display-fill-column-indicator-mode:
> 
> 0. emacs -Q
> 1. M-x global-display-fill-column-indicator-mode RET
> 2. C-x b test1 RET
> 3. RET  ;; this inserts newline to show column indicator
>         ;; that confirms this mode is enabled in the buffer
> 
> 4. M-: (switch-to-buffer (get-buffer-create "test2")) RET
> 5. RET  ;; no column indicator, mode not enabled
> 6. C-h v display-fill-column-indicator-mode RET
>    ;; confirms its value is nil

Sounds like globalized-minor-mode machinery sdomehow doesn't support
the latter method of creating a buffer?  Does the turn-on function of
the mode get called in that scenario?