Document SELinux support functions in Lisp manual.

* doc/lispref/backups.texi (Making Backups): Return value of backup-buffer is
changed.

* doc/lispref/files.texi (File Attributes): Document file-selinux-context.
(Changing Files): Link to it.
(Changing Files): Document set-file-selinux-context.

* fileio.c (Ffile_selinux_context, Fset_file_selinux_context):
Doc fix.

2 files changed, 16 insertions, 6 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 7b546244792..1566d6258af 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,8 @@
 2012-02-25  Chong Yidong  <cyd@gnu.org>
 
+        * fileio.c (Ffile_selinux_context, Fset_file_selinux_context):
+        Doc fix.
+
         * xselect.c (Fx_selection_exists_p): Doc fix.
         (x_clipboard_manager_save_all): Print an informative message
         before saving to clipboard manager.
diff --git a/src/fileio.c b/src/fileio.c
index 839dc07b6ce..7efe919a9f0 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -2798,9 +2798,13 @@ See `file-symlink-p' to distinguish symlinks.  */)
 
 DEFUN ("file-selinux-context", Ffile_selinux_context,
        Sfile_selinux_context, 1, 1, 0,
-       doc: /* Return SELinux context of file named FILENAME,
-as a list ("user", "role", "type", "range"). Return (nil, nil, nil, nil)
-if file does not exist, is not accessible, or SELinux is disabled */)
+       doc: /* Return SELinux context of file named FILENAME.
+The return value is a list (USER ROLE TYPE RANGE), where the list
+elements are strings naming the user, role, type, and range of the
+file's SELinux security context.
+
+Return (nil nil nil nil) if the file is nonexistent or inaccessible,
+or if SELinux is disabled, or if Emacs lacks SELinux support.  */)
   (Lisp_Object filename)
 {
   Lisp_Object absname;
@@ -2853,9 +2857,12 @@ if file does not exist, is not accessible, or SELinux is disabled */)
 
 DEFUN ("set-file-selinux-context", Fset_file_selinux_context,
        Sset_file_selinux_context, 2, 2, 0,
-       doc: /* Set SELinux context of file named FILENAME to CONTEXT
-as a list ("user", "role", "type", "range"). Has no effect if SELinux
-is disabled. */)
+       doc: /* Set SELinux context of file named FILENAME to CONTEXT.
+CONTEXT should be a list (USER ROLE TYPE RANGE), where the list
+elements are strings naming the components of a SELinux context.
+
+This function does nothing if SELinux is disabled, or if Emacs was not
+compiled with SELinux support.  */)
   (Lisp_Object filename, Lisp_Object context)
 {
   Lisp_Object absname;