backport r60544 from trunk:

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.

Misc/NEWS

@@ -244,6 +244,9 @@ Extension Modules
 
 - Bug #1372: zlibmodule.c: int overflow in PyZlib_decompress
 
+- bsddb module: Fix memory leak when using database cursors on
+  databases without a DBEnv.
+
 
 Documentation
 -------------

Modules/_bsddb.c

@@ -913,7 +913,6 @@ DBCursor_dealloc(DBCursorObject* self)
 #endif
 
     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
@@ -922,10 +921,15 @@ DBCursor_dealloc(DBCursorObject* self)
 	   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);
-        self->dbc = NULL;
             MYDB_END_ALLOW_THREADS;
         }
+        self->dbc = NULL;
+    }
     Py_XDECREF( self->mydb );
     PyObject_Del(self);
 }