bug#75398: 30.0.93; files.el documentation refers to "ITS-id" version control

bug#75398: 30.0.93; files.el documentation refers to "ITS-id" version control

[Stefan Kangas]

Severity: wishlist

In files.el, I read this:

    ;;; Commentary:

    ;; Defines most of Emacs's file- and directory-handling functions,
    ;; including basic file visiting, backup generation, link handling,
    ;; ITS-id version control, load- and write-hook handling, and the like.

I understand that "version control" refers to backup files rather than
VCS, but what is "ITS-id"?  I can't find any references to that in the
manual, or by grepping, but since the text was written in 1993, is it
possible that it refers to "Incompatible Time-Sharing System"...?

In any case, I think that part should either be deleted or clarified.

bug#75398: 30.0.93; files.el documentation refers to "ITS-id" version control

[Eli Zaretskii]

> From: Stefan Kangas <stefankangas@gmail.com>
> Date: Mon, 6 Jan 2025 09:46:02 +0000
> 
> Severity: wishlist
> 
> In files.el, I read this:
> 
>     ;;; Commentary:
> 
>     ;; Defines most of Emacs's file- and directory-handling functions,
>     ;; including basic file visiting, backup generation, link handling,
>     ;; ITS-id version control, load- and write-hook handling, and the like.
> 
> I understand that "version control" refers to backup files rather than
> VCS, but what is "ITS-id"?  I can't find any references to that in the
> manual, or by grepping, but since the text was written in 1993, is it
> possible that it refers to "Incompatible Time-Sharing System"...?

Yes, I think ITS was the system which introduced numbered backup
files.  Maybe someone else (Richard?) could confirm.

This commentary was added by Eric Raymond in March 1993.

bug#75398: 30.0.93; files.el documentation refers to "ITS-id" version control

[Stefan Kangas]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Stefan Kangas <stefankangas@gmail.com>
>> Date: Mon, 6 Jan 2025 09:46:02 +0000
>>
>> Severity: wishlist
>>
>> In files.el, I read this:
>>
>>     ;;; Commentary:
>>
>>     ;; Defines most of Emacs's file- and directory-handling functions,
>>     ;; including basic file visiting, backup generation, link handling,
>>     ;; ITS-id version control, load- and write-hook handling, and the like.
>>
>> I understand that "version control" refers to backup files rather than
>> VCS, but what is "ITS-id"?  I can't find any references to that in the
>> manual, or by grepping, but since the text was written in 1993, is it
>> possible that it refers to "Incompatible Time-Sharing System"...?
>
> Yes, I think ITS was the system which introduced numbered backup
> files.  Maybe someone else (Richard?) could confirm.
>
> This commentary was added by Eric Raymond in March 1993.

The question is how do we update this comment to be relevant in 2025.

bug#75398: 30.0.93; files.el documentation refers to "ITS-id" version control

[Eli Zaretskii]

> From: Stefan Kangas <stefankangas@gmail.com>
> Date: Mon, 6 Jan 2025 11:15:26 -0600
> Cc: 75398@debbugs.gnu.org, "Eric S. Raymond" <esr@thyrsus.com>
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> >> From: Stefan Kangas <stefankangas@gmail.com>
> >> Date: Mon, 6 Jan 2025 09:46:02 +0000
> >>
> >> Severity: wishlist
> >>
> >> In files.el, I read this:
> >>
> >>     ;;; Commentary:
> >>
> >>     ;; Defines most of Emacs's file- and directory-handling functions,
> >>     ;; including basic file visiting, backup generation, link handling,
> >>     ;; ITS-id version control, load- and write-hook handling, and the like.
> >>
> >> I understand that "version control" refers to backup files rather than
> >> VCS, but what is "ITS-id"?  I can't find any references to that in the
> >> manual, or by grepping, but since the text was written in 1993, is it
> >> possible that it refers to "Incompatible Time-Sharing System"...?
> >
> > Yes, I think ITS was the system which introduced numbered backup
> > files.  Maybe someone else (Richard?) could confirm.
> >
> > This commentary was added by Eric Raymond in March 1993.
> 
> The question is how do we update this comment to be relevant in 2025.

I'd replace "ITS-id version control" with "version control for
numbered backup files".

bug#75398: 30.0.93; files.el documentation refers to "ITS-id" version control

[Richard Stallman]

[[[ To any NSA and FBI agents reading my email: please consider    ]]]
[[[ whether defending the US Constitution against all enemies,     ]]]
[[[ foreign or domestic, requires you to follow Snowden's example. ]]]

  > I understand that "version control" refers to backup files rather than
  > VCS, but what is "ITS-id"?  I can't find any references to that in the
  > manual, or by grepping, but since the text was written in 1993, is it
  > possible that it refers to "Incompatible Time-Sharing System"...?

It might.  Some of this code may have been translated from TECO in
1984/5.  But I can't recall what it that term might refer to.

On ITS, the only place to store a version number was (1) in the second
filename or (2) in the file contents.  When that text was written, was
there code in Emacs to store a version number in one of those places?


-- 
Dr Richard Stallman (https://stallman.org)
Chief GNUisance of the GNU Project (https://gnu.org)
Founder, Free Software Foundation (https://fsf.org)
Internet Hall-of-Famer (https://internethalloffame.org)

bug#75398: 30.0.93; files.el documentation refers to "ITS-id" version control

[Stefan Kangas]

Eli Zaretskii <eliz@gnu.org> writes:

>> The question is how do we update this comment to be relevant in 2025.
>
> I'd replace "ITS-id version control" with "version control for
> numbered backup files".

Thanks, I opted to fix it in a different way, see commit 1c49edc4080.
Feel free to tweak that.  Meanwhile, I'm closing this bug.

(It's still possible to reply to this bug report for another 90 days.)

bug#75398: 30.0.93; files.el documentation refers to "ITS-id" version control

[Eli Zaretskii]

> Cc: 75398@debbugs.gnu.org
> From: Richard Stallman <rms@gnu.org>
> Date: Tue, 07 Jan 2025 00:10:43 -0500
> 
> On ITS, the only place to store a version number was (1) in the second
> filename or (2) in the file contents.  When that text was written, was
> there code in Emacs to store a version number in one of those places?

Doesn't look like it, I only see the ".~N~" numerical extensions.

You should be able to see the version of files.el at that commit with
this shell command:

  $ git show e41b2db1da153e3ead4a01cb6e729cb99cad78ae:lisp/files.el

Maybe Eric simply had ITS in mind when wrote the commentary, though.