- Improved the check for an "unmapped class",

including the case where the superclass is mapped
but the subclass is not.  Any attempts to access
cls._sa_class_manager.mapper now raise
UnmappedClassError().  [ticket:1142]

1 files changed, 3 insertions, 6 deletions

diff --git a/lib/sqlalchemy/orm/util.py b/lib/sqlalchemy/orm/util.py
index 651b0256b..a2e3c5433 100644
--- a/lib/sqlalchemy/orm/util.py
+++ b/lib/sqlalchemy/orm/util.py
@@ -570,9 +570,9 @@ def object_mapper(instance):
     """
     try:
         state = attributes.instance_state(instance)
-        if not state.manager.mapper:
-            raise exc.UnmappedInstanceError(instance)
         return state.manager.mapper
+    except exc.UnmappedClassError:
+        raise exc.UnmappedInstanceError(instance)
     except exc.NO_STATE:
         raise exc.UnmappedInstanceError(instance)
 
@@ -582,14 +582,11 @@ def class_mapper(class_, compile=True):
     Raises UnmappedClassError if no mapping is configured.
 
     """
+    
     try:
         class_manager = attributes.manager_of_class(class_)
         mapper = class_manager.mapper
 
-        # HACK until [ticket:1142] is complete
-        if mapper is None:
-            raise AttributeError
-
     except exc.NO_STATE:
         raise exc.UnmappedClassError(class_)