bugfix: do not double-close DB cursor during deallocation when the

        underlying DB has already been closed (and thus all of its cursors).
        This fixes a potential segfault.
        SF pybsddb bug id 667343
bugfix: close the DB object when raising an exception due to an error
        during DB.open.  This prevents an exception when closing the
        environment about not all databases being closed.
        SF pybsddb bug id 667340

Lib/bsddb/test/test_basics.py

@@ -398,6 +398,18 @@ class BasicTestCase(unittest.TestCase):
                 self.fail("no exception raised when using a buggy cursor's"
                           "%s method" % method)
 
+        #
+        # free cursor referencing a closed database, it should not barf:
+        #
+        oldcursor = self.d.cursor(txn=txn)
+        self.d.close()
+
+        # this would originally cause a segfault when the cursor for a
+        # closed database was cleaned up.  it should not anymore.
+        # SF pybsddb bug id 667343
+        del oldcursor
+
+
     #----------------------------------------
 
     def test04_PartialGetAndPut(self):

Modules/_bsddb.c

@@ -746,7 +746,8 @@ DBCursor_dealloc(DBCursorObject* self)
     int err;
     if (self->dbc != NULL) {
         MYDB_BEGIN_ALLOW_THREADS;
-        err = self->dbc->c_close(self->dbc);
+	if (self->mydb->db != NULL)
+            err = self->dbc->c_close(self->dbc);
         self->dbc = NULL;
         MYDB_END_ALLOW_THREADS;
     }
@@ -1623,6 +1624,7 @@ DB_open(DBObject* self, PyObject* args, PyObject* kwargs)
 #endif
     MYDB_END_ALLOW_THREADS;
     if (makeDBError(err)) {
+        self->db->close(self->db, 0);
         self->db = NULL;
         return NULL;
     }