Fixed #20865 -- Fixed raw_id_fields to work with callable limit_choices_to.

django/contrib/admin/widgets.py

@@ -116,6 +116,8 @@ def url_params_from_lookup_dict(lookups):
     if lookups and hasattr(lookups, 'items'):
         items = []
         for k, v in lookups.items():
+            if callable(v):
+                v = v()
             if isinstance(v, (tuple, list)):
                 v = ','.join([str(x) for x in v])
             elif isinstance(v, bool):

tests/admin_widgets/tests.py

@@ -226,6 +226,13 @@ class AdminForeignKeyRawIdWidget(DjangoTestCase):
         self.assertEqual(lookup1, {'color__in': 'red,blue'})
         self.assertEqual(lookup1, lookup2)
 
+    def test_url_params_from_lookup_dict_callable(self):
+        def my_callable():
+            return 'works'
+        lookup1 = widgets.url_params_from_lookup_dict({'myfield': my_callable})
+        lookup2 = widgets.url_params_from_lookup_dict({'myfield': my_callable()})
+        self.assertEqual(lookup1, lookup2)
+
 
 class FilteredSelectMultipleWidgetTest(DjangoTestCase):
     def test_render(self):