Fix SF bug #991735, os.access reports true for read-only directories. Will backport
diff --git a/Doc/lib/libos.tex b/Doc/lib/libos.tex
index 2fbecfa..3662a46 100644
--- a/Doc/lib/libos.tex
+++ b/Doc/lib/libos.tex
@@ -692,6 +692,11 @@
open a file before actually doing so using \function{open()} creates a
security hole, because the user might exploit the short time interval
between checking and opening the file to manipulate it.}
+
+\note{I/O operations may fail even when \function{access()}
+indicates that they would succeed, particularly for operations
+on network filesystems which may have permissions semantics
+beyond the usual \POSIX{} permission-bit model.}
\end{funcdesc}
\begin{datadesc}{F_OK}