clarify the behavior of the .first() and .last() methods for empty
databases
this should be backported to the release23-maint branch
diff --git a/Doc/lib/libbsddb.tex b/Doc/lib/libbsddb.tex
index bb1e6b0..a25d39b 100644
--- a/Doc/lib/libbsddb.tex
+++ b/Doc/lib/libbsddb.tex
@@ -135,6 +135,7 @@
\begin{methoddesc}{first}{}
Set the cursor to the first item in the DB file and return it. The order of
keys in the file is unspecified, except in the case of B-Tree databases.
+This method raises \exception{bsddb.error} if the database is empty.
\end{methoddesc}
\begin{methoddesc}{next}{}
@@ -153,6 +154,7 @@
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()}).
+This method raises \exception{bsddb.error} if the database is empty.
\end{methoddesc}
\begin{methoddesc}{sync}{}