After all, this was just a workaround. Remove it.

The real fix was in #171. I leave the tests.

partner_contact_birthdate/models.py

@@ -40,8 +40,7 @@ class Partner(models.Model):
     @api.depends("birthdate_date")
     def _birthdate_compute(self):
         """Store a string of the new date in the old field."""
-        if self.exists():
-            self.birthdate = self.birthdate_date
+        self.birthdate = self.birthdate_date
 
     @api.one
     def _birthdate_inverse(self):

partner_firstname/__openerp__.py

@@ -21,7 +21,7 @@
 {
     'name': 'Partner first name and last name',
     'summary': "Split first name and last name for non company partners",
-    'version': '8.0.2.1.1',
+    'version': '8.0.2.1.0',
     'author': "Camptocamp, Grupo ESOC, Odoo Community Association (OCA)",
     "license": "AGPL-3",
     'maintainer': 'Camptocamp, Acsone',

partner_firstname/models.py

@@ -79,8 +79,7 @@ class ResPartner(models.Model):
     @api.depends("firstname", "lastname")
     def _compute_name(self):
         """Write the 'name' field according to splitted data."""
-        if self.exists():
-            self.name = self._get_computed_name(self.lastname, self.firstname)
+        self.name = self._get_computed_name(self.lastname, self.firstname)
 
     @api.one
     def _inverse_name_after_cleaning_whitespace(self):