Subject: Re: bug#39190: 28.0.50; two buffers with same buffer-file-name (diff-syntax-fontify-props)

From: Stefan Monnier <[email-masked]>
Date: Tue, 18 Feb 2020 08:33:48 -0500

> (defun conf-mode ()
>   ...
>   ;; `conf-mode' plays two roles: it's the parent of several sub-modes
>   ;; but it's also the function that chooses between those submodes.
>   ;; To tell the difference between those two cases where the function
>   ;; might be called, we check `delay-mode-hooks'.
>   ;; (adopted from tex-mode.el)
>   (if (not delay-mode-hooks)
>       ;; try to guess sub-mode of conf-mode based on buffer content

The Right Thing™ to do is of course to split `conf-mode` into two
functions, one for the generic entry point and the other for the shared
parent mode.

How easy/realistic this is, I don't know.

        Stefan