bug#31636: 27.0.50; lockfile syntax searchable from info manual

[Robert Pluim]

Noam Postavsky <npostavs@gmail.com> writes:

> Robert Pluim <rpluim@gmail.com> writes:
>
>> This does mean that if the implementation of locking ever changes,
>> weʼd need to update those docs, but I donʼt think thereʼs much chance
>> of that.
>
> Yes, that's usually the case.  I think you can drop the word "currently"
> from your patch.

OK. V2 attached.

>From 03525a8319ba7a1fb9d1375fa989db0bf9f7feb1 Mon Sep 17 00:00:00 2001
From: Robert Pluim <rpluim@gmail.com>
Date: Tue, 29 May 2018 10:19:16 +0200
Subject: [PATCH] Add more discoverable documentation for '.#'
To: emacs-devel@gnu.org

* doc/emacs/files.texi (Interlocking): Add index entry for '.#' and
mention its use in lockfile names.

* src/filelock.c (Flock_buffer): Mention '.#' string, add reference to
Interlocking info node.
---
 doc/emacs/files.texi | 4 +++-
 src/filelock.c       | 4 +++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/doc/emacs/files.texi b/doc/emacs/files.texi
index 1ced7ca07c..72d538161a 100644
--- a/doc/emacs/files.texi
+++ b/doc/emacs/files.texi
@@ -766,9 +766,11 @@ Interlocking
 
 @findex ask-user-about-lock
 @cindex locking files
+@cindex .#
   When you make the first modification in an Emacs buffer that is
 visiting a file, Emacs records that the file is @dfn{locked} by you.
-(It does this by creating a specially-named symbolic link@footnote{If
+(It does this by creating a specially-named symbolic link, whose name
+contains the string @code{.#} @footnote{If
 your file system does not support symbolic links, a regular file is
 used.} with special contents in the same directory.)  Emacs removes the lock
 when you save the changes.  The idea is that the file is locked
diff --git a/src/filelock.c b/src/filelock.c
index f2dc723407..042fe9e00b 100644
--- a/src/filelock.c
+++ b/src/filelock.c
@@ -773,7 +773,9 @@ DEFUN ("lock-buffer", Flock_buffer, Slock_buffer,
 FILE defaults to current buffer's visited file,
 or else nothing is done if current buffer isn't visiting a file.
 
-If the option `create-lockfiles' is nil, this does nothing.  */)
+If the option `create-lockfiles' is nil, this does nothing.
+The name of the lockfile used contains '.#', see
+Info node `(emacs)Interlocking' for more information.  */)
   (Lisp_Object file)
 {
   if (NILP (file))
-- 
2.17.0.775.ge144d126d7