From 88922d7d5e918f1338eeb9baeecb17ed98ed1261 Mon Sep 17 00:00:00 2001 From: Diederik van der Boor Date: Fri, 11 Mar 2016 17:13:09 +0100 Subject: [PATCH] Fix error when using `date_hierarchy` field in the admin Closes: #201 --- polymorphic/query.py | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/polymorphic/query.py b/polymorphic/query.py index a04f8a1..85e3e75 100644 --- a/polymorphic/query.py +++ b/polymorphic/query.py @@ -194,7 +194,8 @@ class PolymorphicQuerySet(QuerySet): translate_polymorphic_Q_object(self.model, a) elif hasattr(a, 'get_source_expressions'): for source_expression in a.get_source_expressions(): - patch_lookup_gte_18(source_expression) + if source_expression is not None: + patch_lookup_gte_18(source_expression) else: a.name = translate_polymorphic_field_path(self.model, a.name)