diff --git a/bin/osv/orm.py b/bin/osv/orm.py
index 25e63e24ec2..7641e6db8b6 100644
--- a/bin/osv/orm.py
+++ b/bin/osv/orm.py
@@ -2232,7 +2232,10 @@ class orm(orm_template):
             if self.pool._init:
                 self.pool._init_parent[self._name]=True
             else:
-                cr.execute('select parent_left,parent_right from '+self._table+' where id=%s', (vals[self._parent_name],))
+                if vals[self._parent_name]:
+                    cr.execute('select parent_left,parent_right from '+self._table+' where id=%s', (vals[self._parent_name],))
+                else:
+                    cr.execute('SELECT parent_left,parent_right FROM '+self._table+' WHERE id IS NULL')
                 res = cr.fetchone()
                 if res:
                     pleft,pright = res
diff --git a/bin/tools/parse_version.py b/bin/tools/parse_version.py
index 3253ebd5e83..46236aa6080 100644
--- a/bin/tools/parse_version.py
+++ b/bin/tools/parse_version.py
@@ -71,7 +71,7 @@ def parse_version(s):
     contain them.
     """
     parts = []
-    for part in _parse_version_parts(s.lower()):
+    for part in _parse_version_parts((s or '0.1').lower()):
         if part.startswith('*'):
             if part<'*final':   # remove '-' before a prerelease tag
                 while parts and parts[-1]=='*final-': parts.pop()