[IMP] OROM: order_spec is overidden by self._order only if None (aka, not specified at all). False or void order_spec allows to avoid having any order_by clause. This is used now in needaction, to speedup the search.

bzr revid: tde@openerp.com-20121220205102-lx9ftf3l8qg0xqcu

openerp/addons/base/ir/ir_needaction.py

@@ -61,5 +61,5 @@ class ir_needaction_mixin(osv.AbstractModel):
         dom = self._needaction_domain_get(cr, uid, context=context)
         if not dom:
             return 0
-        res = self.search(cr, uid, (domain or []) + dom, limit=1000, order='id DESC', context=context)
+        res = self.search(cr, uid, (domain or []) + dom, limit=1000, order='', context=context)
         return len(res)

openerp/osv/orm.py

@@ -4785,7 +4785,8 @@ class BaseModel(object):
         :raise" except_orm in case order_spec is malformed
         """
         order_by_clause = ''
-        order_spec = order_spec or self._order
+        if order_spec is None:
+            order_spec = self._order
         if order_spec:
             order_by_elements = []
             self._check_qorder(order_spec)