Merge this fix from the pybsddb tree:
r293 | jcea | 2008-01-31 01:08:19 -0800 (Thu, 31 Jan 2008) | 4 lines

Solved memory leak when using cursors with
databases without environment.
diff --git a/Modules/_bsddb.c b/Modules/_bsddb.c
index f407434..7d05b24 100644
--- a/Modules/_bsddb.c
+++ b/Modules/_bsddb.c
@@ -824,7 +824,6 @@
     }
 
     if (self->dbc != NULL) {
-        MYDB_BEGIN_ALLOW_THREADS;
 	/* If the underlying database has been closed, we don't
 	   need to do anything. If the environment has been closed
 	   we need to leak, as BerkeleyDB will crash trying to access
@@ -833,9 +832,14 @@
 	   a database open. */
 	if (self->mydb->db && self->mydb->myenvobj &&
 	    !self->mydb->myenvobj->closed)
+        /* test for: open db + no environment or non-closed environment */
+	if (self->mydb->db && (!self->mydb->myenvobj || (self->mydb->myenvobj &&
+	    !self->mydb->myenvobj->closed))) {
+            MYDB_BEGIN_ALLOW_THREADS;
             err = self->dbc->c_close(self->dbc);
+            MYDB_END_ALLOW_THREADS;
+        }
         self->dbc = NULL;
-        MYDB_END_ALLOW_THREADS;
     }
     Py_XDECREF( self->mydb );
     PyObject_Del(self);