Add warning that last() and previous() don't work for hashtable
databases (opened using hashopen()), as noted by Skip Montanaro on
comp.lang.python.
diff --git a/Doc/lib/libbsddb.tex b/Doc/lib/libbsddb.tex
index 385f558..1af4bdf 100644
--- a/Doc/lib/libbsddb.tex
+++ b/Doc/lib/libbsddb.tex
@@ -104,13 +104,15 @@
\end{methoddesc}
\begin{methoddesc}{previous}{}
-Set the cursor to the first item in the DB file and return it. The order of
-keys in the file is unspecified.
+Set the cursor to the first item in the DB file and return it. The
+order of keys in the file is unspecified. This is not supported on
+hashtable databases (those opened with \function{hashopen()}).
\end{methoddesc}
\begin{methoddesc}{last}{}
-Set the cursor to the last item in the DB file and return it. The order of
-keys in the file is unspecified.
+Set the cursor to the last item in the DB file and return it. The
+order of keys in the file is unspecified. This is not supported on
+hashtable databases (those opened with \function{hashopen()}).
\end{methoddesc}
\begin{methoddesc}{sync}{}