[FIX] Fields.function : Store value computation corrected

lp bug: https://launchpad.net/bugs/421904 fixed

bzr revid: jvo@tinyerp.com-20090922053703-14vmsvuxccsy0ntb

bin/osv/orm.py

@@ -2706,6 +2706,8 @@ class orm(orm_template):
         for fnct in range(len(fncts)):
             if fncts[fnct][3]:
                 ok = False
+                if not fields:
+                    ok = True
                 for f in (fields or []):
                     if f in fncts[fnct][3]:
                         ok = True