[PATCH 21.5] #'expand-file-name documentation

Hi all

As discussed on xemacs-beta, here a proposal for a doc string fix to
get things going.

Best regards
Marcus

diff -r cb65bfaf7110 src/ChangeLog
--- a/src/ChangeLog	Fri Mar 27 16:05:15 2015 +0100
+++ b/src/ChangeLog	Tue Jul 21 21:44:04 2015 +0200
@@ -1,3 +1,8 @@
+2015-07-21  Marcus Harnisch  <[email protected]>
+
+	* fileio.c (expand-file-name): Document behavior for
+	 file names that expand to locations above (outside) `/'
+
 2015-06-22  Michael Sperber  <[email protected]>
 
 	* redisplay-xlike-inc.c (XFT_FROB_LISP_COLOR): Use
diff -r cb65bfaf7110 src/fileio.c
--- a/src/fileio.c	Fri Mar 27 16:05:15 2015 +0100
+++ b/src/fileio.c	Tue Jul 21 21:44:04 2015 +0200
@@ -721,6 +721,10 @@
 file names in the file system.
 An initial `~/' expands to your home directory.
 An initial `~USER/' expands to USER's home directory.
+Behavior with file names that expand to locations above (outside) `/'
+via parent reference `..' is not well specified and returned results
+could be considered unintuitive. It is normally easy to work around
+this limitation at application level.
 See also the function `substitute-in-file-name'.
 */
        (name, default_directory))