Document SELinux support.

* doc/lispref/files.texi (Changing Files): Document SELinux support.
* etc/NEWS: Markup.

doc/lispref/ChangeLog

 2012-01-29  Glenn Morris  <rgm@gnu.org>
 
+	* files.texi (Changing Files): Document SELinux support.
+
 	* windows.texi (Window Sizes): Fix typo.
 
 2012-01-28  Chong Yidong  <cyd@gnu.org>

doc/lispref/files.texi

@@ -1480,7 +1480,7 @@ with @code{add-name-to-file} and then deleting @var{filename} has the
 same effect as renaming, aside from momentary intermediate states.
 @end deffn
 
-@deffn Command copy-file oldname newname &optional ok-if-exists time preserve-uid-gid
+@deffn Command copy-file oldname newname &optional ok-if-exists time preserve-uid-gid preserve-selinux
 This command copies the file @var{oldname} to @var{newname}.  An
 error is signaled if @var{oldname} does not exist.  If @var{newname}
 names a directory, it copies @var{oldname} into that directory,
@@ -1501,6 +1501,19 @@ usually set to the user running Emacs).  If @var{preserve-uid-gid} is
 non-@code{nil}, we attempt to copy the user and group ownership of the
 file.  This works only on some operating systems, and only if you have
 the correct permissions to do so.
+
+@cindex SELinux
+If the optional argument @var{preserve-selinux} is non-@code{nil}, we
+attempt to copy the SELinux@footnote{@samp{Security-Enhanced Linux}
+is a kernel feature that allows for finer access controls to be set on
+files, and a system security policy to define who can access what.
+The functions @code{file-selinux-context} and @code{set-file-selinux-context}
+get and set, respectively, the SELinux properties of a file.}
+context of the file.  For this to work, Emacs must have been built
+with libselinux support.
+
+Functions like @code{backup-buffer} use these optional arguments
+to preserve information about their input files.
 @end deffn
 
 @deffn Command make-symbolic-link filename newname  &optional ok-if-exists

etc/NEWS

@@ -24,8 +24,10 @@ so we will look at it and add it to the manual.
 
 * Installation Changes in Emacs 24.1
 
+---
 ** Configure links against libselinux if it is found.
-You can disable this by using --without-selinux.
+You can disable this by using --without-selinux.  See below for
+information on SELinux support.
 
 ---
 ** By default, the installed Info and man pages are compressed.
@@ -263,14 +265,17 @@ Emacs.pane.menubar.font:  Courier-12
 Also, the first dash (which does not indicate anything) is just
 displayed as a space.
 
++++
 ** Basic SELinux support has been added.
 This requires Emacs to be linked with libselinux at build time.
 
++++
 *** Emacs preserves the SELinux file context when backing up, and
 optionally when copying files. To this end, copy-file has an extra
 optional argument, and backup-buffer and friends include the SELinux
 context in their return values.
 
++++
 *** The new functions file-selinux-context and set-file-selinux-context
 get and set the SELinux context of a file.
 ---