Add detailed documentation about lock files

* doc/emacs/files.texi (Interlocking): Point user at detailed
file locking description in lisp reference manual.  Add index
entry for '.#' to improve disoverability of information about locking.

* doc/lispref/files.texi (File Locks): Describe in detail what
the form of the lock file is.  Add index entry for '.#' to
improve disoverability of information about locking.

* src/filelock.c (create-lockfiles): Add cross reference to
file locking in user manual and to 'lock-buffer'.  Add string
'.#' to help users find the doc string.

1 files changed, 4 insertions, 1 deletions

diff --git a/src/filelock.c b/src/filelock.c
index f2dc7234076..d33063c8790 100644
--- a/src/filelock.c
+++ b/src/filelock.c
@@ -849,7 +849,10 @@ syms_of_filelock (void)
   Vtemporary_file_directory = Qnil;
 
   DEFVAR_BOOL ("create-lockfiles", create_lockfiles,
-               doc: /* Non-nil means use lockfiles to avoid editing collisions.  */);
+               doc: /* Non-nil means use lockfiles to avoid editing collisions.
+The name of the (per-buffer) lockfile is constructed by prepending a
+'.#' to the name of the file being locked.  See also `lock-buffer' and
+Info node `(emacs)Interlocking'.  */);
   create_lockfiles = 1;
 
   defsubr (&Sunlock_buffer);