have paths represented as their actual mapper, not the base mapper, allowing

more information for custom mapper opts to see what's going on.  add a new _reduce_path()
function to apply to the path as stored in dictionaries, adds a slight cost overhead.

1 files changed, 3 insertions, 3 deletions

diff --git a/lib/sqlalchemy/orm/query.py b/lib/sqlalchemy/orm/query.py
index 5b2fbb524..c90c163e9 100644
--- a/lib/sqlalchemy/orm/query.py
+++ b/lib/sqlalchemy/orm/query.py
@@ -1967,7 +1967,7 @@ class _MapperEntity(_QueryEntity):
         if is_aliased_class:
             self.path_entity = self.entity = self.entity_zero = entity
         else:
-            self.path_entity = mapper.base_mapper
+            self.path_entity = mapper
             self.entity = self.entity_zero = mapper
 
     def set_with_polymorphic(self, query, cls_or_mappers, selectable, discriminator):
@@ -1989,7 +1989,7 @@ class _MapperEntity(_QueryEntity):
         if _is_aliased_class(entity):
             return entity is self.path_entity
         else:
-            return entity.base_mapper is self.path_entity
+            return entity.isa(self.path_entity)
 
     def adapt_to_selectable(self, query, sel):
         query._entities.append(self)
@@ -2151,7 +2151,7 @@ class _ColumnEntity(_QueryEntity):
             return entity is self.entity_zero
         else:
             return not _is_aliased_class(self.entity_zero) and \
-                    entity.base_mapper.common_parent(self.entity_zero)
+                    entity.common_parent(self.entity_zero)
 
     def _resolve_expr_against_query_aliases(self, query, expr, context):
         return query._adapt_clause(expr, False, True)