[ADD] added comment in _validate() explaining why the context is not passed around when calling _constraints functions.

bzr revid: vmt@openerp.com-20121205082840-2ww34gbs7nl56952

openerp/osv/orm.py

@@ -1524,6 +1524,8 @@ class BaseModel(object):
         error_msgs = []
         for constraint in self._constraints:
             fun, msg, fields = constraint
+            # We don't pass around the context here: validation code
+            # must always yield the same results.
             if not fun(self, cr, uid, ids):
                 # Check presence of __call__ directly instead of using
                 # callable() because it will be deprecated as of Python 3.0