[FIX] Marshall frozendict in XMLRPC controller

PR #42723 changed the public method context_get on res.users return a
frozendict instead of a classic CPython dict.

Since the default XMLRPC Marshaller does not know how to serialize a
frozendict, this would result in errors when calling the method directly
via the XMLRPC layer.

This commit solves this issue by defining a marshalling procedure for
frozendict objects in our custom OdooMarshaller class, this simply
converts the frozendict into a dict and uses the default dict-to-xml
dump procedure (dump_struct).

Fixes #75412

closes odoo/odoo#75478

X-original-commit: e80a299ed910cacac4aa4e64164909af36ce62ad
Signed-off-by: Adrian Torres (adt) <adt@odoo.com>

odoo/addons/base/controllers/rpc.py

@@ -9,6 +9,7 @@ from odoo.http import Controller, dispatch_rpc, request, route
 from odoo.service import wsgi_server
 from odoo.fields import Date, Datetime, Command
 from odoo.tools import lazy
+from odoo.tools.misc import frozendict
 
 
 class OdooMarshaller(xmlrpc.client.Marshaller):
@@ -19,6 +20,11 @@ class OdooMarshaller(xmlrpc.client.Marshaller):
 
     dispatch = dict(xmlrpc.client.Marshaller.dispatch)
 
+    def dump_frozen_dict(self, value, write):
+        value = dict(value)
+        self.dump_struct(value, write)
+    dispatch[frozendict] = dump_frozen_dict
+
     def dump_datetime(self, value, write):
         # override to marshall as a string for backwards compatibility
         value = Datetime.to_string(value)

odoo/addons/base/tests/test_xmlrpc.py

@@ -62,6 +62,15 @@ class TestXMLRPC(common.HttpCase):
         [x] = self.xmlrpc('res.users', 'read', r.id, ['signature'])
         self.assertEqual(x['signature'], sig)
 
+    def test_xmlrpc_frozendict_marshalling(self):
+        """ Test that the marshalling of a frozendict object works properly over XMLRPC """
+        ctx = self.xmlrpc_object.execute(
+            common.get_db_name(), self.admin_uid, 'admin',
+            'res.users', 'context_get',
+        )
+        self.assertEqual(ctx['lang'], 'en_US')
+        self.assertEqual(ctx['tz'], 'Europe/Brussels')
+
     def test_jsonrpc_read_group(self):
         self._json_call(
             common.get_db_name(), self.admin_uid, 'admin',