Fix bug #422702: Make flag argument to open optional, and document it that way.
diff --git a/Doc/lib/libdbhash.tex b/Doc/lib/libdbhash.tex
index 61b0163..d3ed0da 100644
--- a/Doc/lib/libdbhash.tex
+++ b/Doc/lib/libdbhash.tex
@@ -21,7 +21,7 @@
\exception{KeyError}. It is a synonym for \exception{bsddb.error}.
\end{excdesc}
-\begin{funcdesc}{open}{path, flag\optional{, mode}}
+\begin{funcdesc}{open}{path, \optional{, flag\optional{, mode}}}
Open a \code{db} database and return the database object. The
\var{path} argument is the name of the database file.