[IMP] fields: split multi-purpose '_origin' into 'column' and 'inherited'

This makes it easier to determine when a field interfaces a column, and when it
implements an inherited field (with _inherits).

openerp/addons/base/res/res_users.py

@@ -190,8 +190,8 @@ class res_users(osv.osv):
 
     # overridden inherited fields to bypass access rights, in case you have
     # access to the user but not its corresponding partner
-    name = openerp.fields.Char(related='partner_id.name')
-    email = openerp.fields.Char(related='partner_id.email')
+    name = openerp.fields.Char(related='partner_id.name', inherited=True)
+    email = openerp.fields.Char(related='partner_id.email', inherited=True)
 
     def on_change_login(self, cr, uid, ids, login, context=None):
         if login and tools.single_email_re.match(login):

openerp/fields.py

@@ -249,7 +249,8 @@ class Field(object):
     _free_attrs = None          # list of semantic-free attribute names
 
     automatic = False           # whether the field is automatically created ("magic" field)
-    _origin = None              # the column or field interfaced by self, if any
+    inherited = False           # whether the field is inherited (_inherits)
+    column = None               # the column interfaced by the field
 
     name = None                 # name of the field
     type = None                 # type of the field (string)
@@ -580,11 +581,10 @@ class Field(object):
     def to_column(self):
         """ return a low-level field object corresponding to `self` """
         assert self.store
-        if self._origin:
-            assert isinstance(self._origin, fields._column)
+        if self.column:
             # some columns are registry-dependent, like float fields (digits);
             # duplicate them to avoid sharing between registries
-            return copy(self._origin)
+            return copy(self.column)
 
         _logger.debug("Create fields._column for Field %s", self)
         args = {}

openerp/models.py

@@ -813,7 +813,7 @@ class BaseModel(object):
         # inheritance between different models)
         cls._fields = {}
         for attr, field in getmembers(cls, Field.__instancecheck__):
-            if not field._origin:
+            if not field.inherited:
                 cls._add_field(attr, field.copy())
 
         # introduce magic fields
@@ -2950,9 +2950,9 @@ class BaseModel(object):
             for attr, field in cls.pool[parent_model]._fields.iteritems():
                 if attr not in cls._fields:
                     cls._add_field(attr, field.copy(
+                        inherited=True,
                         related=(parent_field, attr),
                         related_sudo=False,
-                        _origin=field,
                     ))
 
         cls._inherits_reload_src()

openerp/osv/fields.py

@@ -131,7 +131,7 @@ class _column(object):
     def to_field_args(self):
         """ return a dictionary with all the arguments to pass to the field """
         items = [
-            ('_origin', self),                  # field interfaces self
+            ('column', self),                   # field interfaces self
             ('copy', self.copy),
             ('index', self.select),
             ('manual', self.manual),