change Movement.getTotalPrice to returns 0.0 by default.

Delivery and Order's getTotalPrice usually sum getTotalPrice for the enclosed
movements, so it's better not to return None.


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@21207 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/Document/Movement.py

@@ -280,7 +280,7 @@ class Movement(XMLObject, Amount):
 
   security.declareProtected( Permissions.AccessContentsInformation,
                              'getTotalPrice')
-  def getTotalPrice(self, default=None, context=None, REQUEST=None, fast=None,
+  def getTotalPrice(self, default=0.0, context=None, REQUEST=None, fast=None,
                     **kw):
     """Return the total price in the context.