bug#18205: Obsolete patterns in auto-mode-alist

[Eli Zaretskii]

> Date: Wed, 6 Aug 2014 00:58:04 +0100
> From: Reuben Thomas <rrt@sc3d.org>
> 
>      ;; .emacs or .gnus or .viper following a directory delimiter in
>      ;; Unix, MSDOG or VMS syntax.
>      ("[]>:/\\]\\..*\\(emacs\\|gnus\\|viper\\)\\'" . emacs-lisp-mode)
>      ("\\`\\..*emacs\\'" . emacs-lisp-mode)
>      ;; _emacs following a directory delimiter
>      ;; in MsDos syntax
>      ("[:/]_emacs\\'" . emacs-lisp-mode)
> 
> There are two non-standard spellings:
> 
> s/MSDOG/MS-DOS/
> s/MsDos/MS-DOS/
> 
> Further, the second line looks like it will only match a .emacs in the root
> directory

No, it matches .emacs with no leading directories at all.

> Given that VMS support has been removed, can we replace the first two
> pattern lines with a line that uses the pattern used above:
> 
> \\(/\\|\\`\\)

No, that's not enough: it will miss "c:.emacs".

IMO, it's OK to remove the VMS-specific characters (AFAIK, the first 2
in the character class), but the rest should stay.

> And can we then also remove the third line, as MS-DOS syntax is not
> treated specially anywhere else in this default value?

How can you remove it, and still support _emacs as a file whose
normal-mode is emacs-lisp?  _emacs is supported on MS-DOS and
MS-Windows.  (I don't understand what you meant by "not supported
specially anywhere else".)