[FIX] base: ensure existing ir.model.constraint xmlids are loaded

When we load a module and the SQL constraints exist both in the table
and in `ir_model_constraint` we need to ensure the xmlid is loaded.
Otherwise the record in `ir_model_constraint` is removed.

Since 4c9968397b we skip returning
existing non-updated constraint records in `_reflect_constraint`. This
leads to them being removed by the ORM. At the end of the load the ORM
sees the record in `ir_model_data` but not in the xmlid pool, thus it
removes it.

closes odoo/odoo#162105

X-original-commit: b5670c7f0d35d13affee2ae93158556346b7dd23
Signed-off-by: Christophe Simonis (chs) <chs@odoo.com>

odoo/addons/base/models/ir_model.py

@@ -1873,9 +1873,11 @@ class IrModelConstraint(models.Model):
             conname = '%s_%s' % (model._table, key)
             module = constraint_module.get(key)
             record = self._reflect_constraint(model, conname, 'u', cons_text(definition), module, message)
+            xml_id = '%s.constraint_%s' % (module, conname)
             if record:
-                xml_id = '%s.constraint_%s' % (module, conname)
                 data_list.append(dict(xml_id=xml_id, record=record))
+            else:
+                self.env['ir.model.data']._load_xmlid(xml_id)
         if data_list:
             self.env['ir.model.data']._update_xmlids(data_list)
 

odoo/addons/base/tests/test_ir_actions.py

@@ -736,7 +736,7 @@ class TestCustomFields(TestCommonCustomFields):
 
         # create a non-computed field, and assert how many queries it takes
         model_id = self.env['ir.model']._get_id('res.partner')
-        query_count = 44
+        query_count = 48
         with self.assertQueryCount(query_count):
             self.env.registry.clear_cache()
             self.env['ir.model.fields'].create({