Document patch #594001.
diff --git a/Doc/lib/libos.tex b/Doc/lib/libos.tex
index 5cbeeeb..afbea54 100644
--- a/Doc/lib/libos.tex
+++ b/Doc/lib/libos.tex
@@ -635,6 +635,12 @@
Availability: Macintosh, \UNIX, Windows.
\end{funcdesc}
+\begin{funcdesc}{getcwdu}{}
+Return a Unicode object representing the current working directory.
+Availability: \UNIX, Windows.
+\versionadded{2.3}
+\end{funcdesc}
+
\begin{funcdesc}{chroot}{path}
Change the root directory of the current process to \var{path}.
Availability: \UNIX.
@@ -670,6 +676,9 @@
entries \code{'.'} and \code{'..'} even if they are present in the
directory.
Availability: Macintosh, \UNIX, Windows.
+
+\versionadded[On Windows NT/2k/XP, if \var{path} is a Unicode object,
+the result will be a list of Unicode objects.]{2.3}
\end{funcdesc}
\begin{funcdesc}{lstat}{path}