[FIX] models: do not load custom fields with depends when partial=True

Upgrading a module in the presence of computed custom fields can fail, if a
computed custom field depends on another field from a module that is not loaded
yet.  The patch simply prevents custom fields with dependencies from being
loaded in partial mode.

openerp/models.py

@@ -728,6 +728,8 @@ class BaseModel(object):
                 attrs['domain'] = eval(field['domain']) if field['domain'] else None
             # add compute function if given
             if field['compute']:
+                if partial and field['depends']:
+                    continue
                 attrs['compute'] = make_compute(field['compute'], field['depends'])
             self._add_field(name, Field.by_type[field['ttype']](**attrs))