diff --git a/openerp/fields.py b/openerp/fields.py
index df1433087cb..9165ddfde1f 100644
--- a/openerp/fields.py
+++ b/openerp/fields.py
@@ -289,14 +289,9 @@ class Field(object):
         self._attrs = {key: val for key, val in kwargs.iteritems() if val is not None}
         self._free_attrs = []
 
-    def copy(self, **kwargs):
-        """ copy(item) -> test
-
-        make a copy of `self`, possibly modified with parameters `kwargs` """
-        field = copy(self)
-        field._attrs = {key: val for key, val in kwargs.iteritems() if val is not None}
-        field._free_attrs = list(self._free_attrs)
-        return field
+    def new(self, **kwargs):
+        """ Return a field of the same type as `self`, with its own parameters. """
+        return type(self)(**kwargs)
 
     def set_class_name(self, cls, name):
         """ Assign the model class and field name of `self`. """
@@ -434,12 +429,17 @@ class Field(object):
         if isinstance(self.related, basestring):
             self.related = tuple(self.related.split('.'))
 
-        # determine the related field, and make sure it is set up
+        # determine the chain of fields, and make sure they are all set up
+        fields = []
         recs = env[self.model_name]
-        for name in self.related[:-1]:
+        for name in self.related:
+            fields.append(recs._fields[name])
             recs = recs[name]
-        field = self.related_field = recs._fields[self.related[-1]]
-        field.setup(env)
+
+        for field in fields:
+            field.setup(env)
+
+        self.related_field = field = fields[-1]
 
         # check type consistency
         if self.type != field.type:
@@ -458,6 +458,10 @@ class Field(object):
             if not getattr(self, attr):
                 setattr(self, attr, getattr(field, prop))
 
+        # special case: required
+        if not self.required:
+            self.required = all(field.required for field in fields)
+
     def _compute_related(self, records):
         """ Compute the related field `self` on `records`. """
         # when related_sudo, bypass access rights checks when reading values
@@ -486,6 +490,7 @@ class Field(object):
         return [('.'.join(self.related), operator, value)]
 
     # properties used by _setup_related() to copy values from related field
+    _related_comodel_name = property(attrgetter('comodel_name'))
     _related_string = property(attrgetter('string'))
     _related_help = property(attrgetter('help'))
     _related_readonly = property(attrgetter('readonly'))
@@ -1354,6 +1359,17 @@ class _Relational(Field):
         assert self.comodel_name in env.registry, \
             "Field %s with unknown comodel_name %r" % (self, self.comodel_name)
 
+    @property
+    def _related_domain(self):
+        if callable(self.domain):
+            # will be called with another model than self's
+            return lambda recs: self.domain(recs.env[self.model_name])
+        else:
+            # maybe not correct if domain is a string...
+            return self.domain
+
+    _related_context = property(attrgetter('context'))
+
     _description_relation = property(attrgetter('comodel_name'))
     _description_context = property(attrgetter('context'))
 
diff --git a/openerp/models.py b/openerp/models.py
index 2562e108410..bb54260e5fe 100644
--- a/openerp/models.py
+++ b/openerp/models.py
@@ -811,7 +811,7 @@ class BaseModel(object):
         cls._fields = {}
         for attr, field in getmembers(cls, Field.__instancecheck__):
             if not field.inherited:
-                cls._add_field(attr, field.copy())
+                cls._add_field(attr, field.new())
 
         # introduce magic fields
         cls._add_magic_fields()
@@ -2914,7 +2914,7 @@ class BaseModel(object):
         for parent_model, parent_field in reversed(cls._inherits.items()):
             for attr, field in cls.pool[parent_model]._fields.iteritems():
                 if attr not in cls._fields:
-                    cls._add_field(attr, field.copy(
+                    cls._add_field(attr, field.new(
                         inherited=True,
                         related=(parent_field, attr),
                         related_sudo=False,