Fix sorting for aliased

sqlalchemy_utils/functions/orm.py

@@ -672,6 +672,9 @@ def get_descriptor(entity, attr):
             else:
                 # Handle synonyms, relationship properties and hybrid
                 # properties
+
+                if isinstance(entity, sa.orm.util.AliasedClass):
+                    return getattr(entity, attr)
                 try:
                     return getattr(mapper.class_, attr)
                 except AttributeError:

tests/__init__.py

@@ -75,6 +75,15 @@ class TestCase(object):
             __tablename__ = 'category'
             id = sa.Column(sa.Integer, primary_key=True)
             name = sa.Column(sa.Unicode(255))
+            title = sa.Column(sa.Unicode(255))
+
+            @hybrid_property
+            def full_name(self):
+                return u'%s %s' % (self.title, self.name)
+
+            @full_name.expression
+            def full_name(self):
+                return sa.func.concat(self.title, ' ', self.name)
 
             @hybrid_property
             def articles_count(self):

tests/test_sort_query.py

@@ -211,6 +211,23 @@ class TestSortQueryRelationshipCounts(TestCase):
         query = sort_query(query, '-categories-articles_count')
         assert_contains('ORDER BY (SELECT count(article.id) AS count_1', query)
 
+    def test_aliased_concat_hybrid_property(self):
+        alias = sa.orm.aliased(
+            self.Category,
+            name='aliased'
+        )
+        query = (
+            self.session.query(self.Article)
+            .outerjoin(alias, self.Article.category)
+            .options(
+                sa.orm.contains_eager(self.Article.category, alias=alias)
+            )
+        )
+        query = sort_query(query, 'aliased-full_name')
+        assert_contains(
+            'concat(aliased.title, :param_1, aliased.name)', query
+        )
+
 
 class TestSortQueryWithPolymorphicInheritance(TestCase):
     """