[IMP] fields: inherited field on new record are set on parent records

This makes the behavior of `onchange()` consistent in the case of
inherited models (with `_inherits`).

closes odoo/odoo#45910

Signed-off-by: Raphael Collet (rco) <rco@openerp.com>

2 files changed, 30 insertions, 2 deletions

diff --git a/odoo/addons/test_new_api/tests/test_new_fields.py b/odoo/addons/test_new_api/tests/test_new_fields.py
index 0f6c7fe9bb5..b98b1a34c0f 100644
--- a/odoo/addons/test_new_api/tests/test_new_fields.py
+++ b/odoo/addons/test_new_api/tests/test_new_fields.py
@@ -1216,6 +1216,20 @@ class TestFields(TransactionCaseWithUserDemo):
         # check that this does not generate an infinite recursion
         new_disc._convert_to_write(new_disc._cache)
 
+    def test_40_new_inherited_fields(self):
+        """ Test the behavior of new records with inherited fields. """
+        email = self.env['test_new_api.emailmessage'].new({'body': 'XXX'})
+        self.assertEqual(email.body, 'XXX')
+        self.assertEqual(email.message.body, 'XXX')
+
+        email.body = 'YYY'
+        self.assertEqual(email.body, 'YYY')
+        self.assertEqual(email.message.body, 'YYY')
+
+        email.message.body = 'ZZZ'
+        self.assertEqual(email.body, 'ZZZ')
+        self.assertEqual(email.message.body, 'ZZZ')
+
     def test_40_new_ref_origin(self):
         """ Test the behavior of new records with ref/origin. """
         Discussion = self.env['test_new_api.discussion']
diff --git a/odoo/fields.py b/odoo/fields.py
index 64b8083df7c..bcf8bc6a8f0 100644
--- a/odoo/fields.py
+++ b/odoo/fields.py
@@ -1010,8 +1010,17 @@ class Field(MetaField('DummyField', (object,), {})):
                 env.cache.set(record, self, value)
 
             elif (not record.id) and self.type == 'many2one' and self.delegate:
-                # special case: parent records are new as well
-                parent = record.env[self.comodel_name].new()
+                # the parent record is also a new record, with the same cached
+                # values as record for the corresponding inherited fields
+                def is_inherited_field(name):
+                    field = record._fields[name]
+                    return field.inherited and field.related[0] == self.name
+
+                parent = record.env[self.comodel_name].new({
+                    name: value
+                    for name, value in record._cache.items()
+                    if is_inherited_field(name)
+                })
                 value = self.convert_to_cache(parent, record)
                 env.cache.set(record, self, value)
 
@@ -1089,6 +1098,11 @@ class Field(MetaField('DummyField', (object,), {})):
                 if self.relational:
                     new_records.modified([self.name])
 
+            if self.inherited:
+                # special case: also assign parent records if they are new
+                parents = records[self.related[0]]
+                parents.filtered(lambda r: not r.id)[self.name] = value
+
         if other_ids:
             # base case: full business logic
             records = records.browse(other_ids)