- a change to the previous __mapper_args__ commit.

- the __mapper_args__ dict is copied when propagating to a subclass,
and is taken straight off the class __dict__ to avoid any
propagation from the parent.  mapper inheritance already
propagates the things you want from the parent mapper.
[ticket:1393]

1 files changed, 5 insertions, 2 deletions

diff --git a/lib/sqlalchemy/ext/declarative.py b/lib/sqlalchemy/ext/declarative.py
index cc972fc6f..43177e2e2 100644
--- a/lib/sqlalchemy/ext/declarative.py
+++ b/lib/sqlalchemy/ext/declarative.py
@@ -499,8 +499,11 @@ def _as_declarative(cls, classname, dict_):
                 if not table.c.contains_column(c):
                     raise exceptions.ArgumentError(
                                 "Can't add additional column %r when specifying __table__" % key)
-            
-    mapper_args = dict(getattr(cls, '__mapper_args__', {}))
+    
+    if '__mapper_args__' in dict_:
+        mapper_args = dict(dict_['__mapper_args__'])
+    else:
+        mapper_args = {}
     if 'inherits' not in mapper_args:
         for c in cls.__bases__:
             if _is_mapped_class(c):