- Fixed bug whereby deferred() columns with a group in conjunction

with an otherwise unrelated synonym() would produce
an AttributeError during deferred load.

3 files changed, 23 insertions, 2 deletions

diff --git a/CHANGES b/CHANGES
index be0d9aab0..9b163c7c9 100644
--- a/CHANGES
+++ b/CHANGES
@@ -39,6 +39,10 @@ CHANGES
     - Fixed primary key update for many-to-many collections where
       the collection had not been loaded yet [ticket:1127]
 
+    - Fixed bug whereby deferred() columns with a group in conjunction
+      with an otherwise unrelated synonym() would produce 
+      an AttributeError during deferred load.
+      
     - The before_flush() hook on SessionExtension takes place before
       the list of new/dirty/deleted is calculated for the final
       time, allowing routines within before_flush() to further
diff --git a/lib/sqlalchemy/orm/strategies.py b/lib/sqlalchemy/orm/strategies.py
index e0166e56c..f254052ec 100644
--- a/lib/sqlalchemy/orm/strategies.py
+++ b/lib/sqlalchemy/orm/strategies.py
@@ -13,7 +13,7 @@ from sqlalchemy.sql import visitors, expression, operators
 from sqlalchemy.orm import mapper, attributes
 from sqlalchemy.orm.interfaces import (
     LoaderStrategy, StrategizedOption, MapperOption, PropertyOption,
-    serialize_path, deserialize_path
+    serialize_path, deserialize_path, StrategizedProperty
     )
 from sqlalchemy.orm import session as sessionlib
 from sqlalchemy.orm import util as mapperutil
@@ -247,7 +247,13 @@ class LoadDeferredColumns(object):
         if self.keys:
             toload = self.keys
         elif strategy.group:
-            toload = [p.key for p in localparent.iterate_properties if isinstance(p.strategy, DeferredColumnLoader) and p.group==strategy.group]
+            toload = [
+                    p.key for p in 
+                    localparent.iterate_properties 
+                    if isinstance(p, StrategizedProperty) and 
+                      isinstance(p.strategy, DeferredColumnLoader) and 
+                      p.group==strategy.group
+                    ]
         else:
             toload = [self.key]
 
diff --git a/test/orm/mapper.py b/test/orm/mapper.py
index bcc75e402..ce47c164a 100644
--- a/test/orm/mapper.py
+++ b/test/orm/mapper.py
@@ -1144,6 +1144,17 @@ class DeferredTest(_fixtures.FixtureTest):
         self.sql_count_(0, go)
 
     @testing.resolve_artifact_names
+    def test_synonym_group_bug(self):
+        mapper(Order, orders, properties={
+            'isopen':synonym('_isopen', map_column=True),
+            'description':deferred(orders.c.description, group='foo')
+        })
+        
+        sess = create_session()
+        o1 = sess.query(Order).get(1)
+        eq_(o1.description, "order 1")
+
+    @testing.resolve_artifact_names
     def test_unsaved_2(self):
         mapper(Order, orders, properties={
             'description': deferred(orders.c.description)})