[IMP] api: in todo list, group records to recompute by environment

The effect of this change is to trigger the recomputation of fields on larger
recordsets.  This takes advantage of batch computations within compute methods.

openerp/api.py

@@ -832,7 +832,8 @@ class Environment(object):
             with all records to recompute for ``field``.
         """
         if field in self.all.todo:
-            return reduce(operator.or_, self.all.todo[field])
+            ids = set(rid for recs in self.all.todo[field] for rid in recs.ids)
+            return self[field.model_name].browse(ids)
 
     def check_todo(self, field, record):
         """ Check whether ``field`` must be recomputed on ``record``, and if so,
@@ -845,7 +846,12 @@ class Environment(object):
     def add_todo(self, field, records):
         """ Mark ``field`` to be recomputed on ``records``. """
         recs_list = self.all.todo.setdefault(field, [])
-        recs_list.append(records)
+        for i, recs in enumerate(recs_list):
+            if recs.env == records.env:
+                recs_list[i] |= records
+                break
+        else:
+            recs_list.append(records)
 
     def remove_todo(self, field, records):
         """ Mark ``field`` as recomputed on ``records``. """