- Fixed bug which is actually a regression that occurred between

versions 0.8.0 and 0.8.1, due :ticket:`2714`.  The case where
joined eager loading needs to join out over a subclass-bound
relationship when "with_polymorphic" were also used would fail
to join from the correct entity.
fixes #3593

1 files changed, 5 insertions, 1 deletions

diff --git a/lib/sqlalchemy/orm/util.py b/lib/sqlalchemy/orm/util.py
index 4351c8dc6..46183a47d 100644
--- a/lib/sqlalchemy/orm/util.py
+++ b/lib/sqlalchemy/orm/util.py
@@ -537,7 +537,11 @@ class AliasedInsp(InspectionAttr):
     def _entity_for_mapper(self, mapper):
         self_poly = self.with_polymorphic_mappers
         if mapper in self_poly:
-            return getattr(self.entity, mapper.class_.__name__)._aliased_insp
+            if mapper is self.mapper:
+                return self
+            else:
+                return getattr(
+                    self.entity, mapper.class_.__name__)._aliased_insp
         elif mapper.isa(self.mapper):
             return self
         else: