- merge of trunk r6611

- Fixed a column arithmetic bug that affected column
correspondence for cloned selectables which contain
free-standing column expressions.   This bug is
generally only noticeable when exercising newer
ORM behavior only availble in 0.6 via [ticket:1568],
but is more correct at the SQL expression level
as well. [ticket:1617]

3 files changed, 24 insertions, 2 deletions

diff --git a/CHANGES b/CHANGES
index 305ca2b98..b25239af8 100644
--- a/CHANGES
+++ b/CHANGES
@@ -11,7 +11,15 @@ CHANGES
       unnamed Column objects. This allows easy creation of 
       declarative helpers which place common columns on multiple 
       subclasses.
-      
+    
+    - Fixed a column arithmetic bug that affected column
+      correspondence for cloned selectables which contain
+      free-standing column expressions.   This bug is
+      generally only noticeable when exercising newer 
+      ORM behavior only availble in 0.6 via [ticket:1568], 
+      but is more correct at the SQL expression level 
+      as well. [ticket:1617]
+    
 - postgresql
     - The extract() function, which was slightly improved in
       0.5.7, needed a lot more work to generate the correct
diff --git a/lib/sqlalchemy/sql/expression.py b/lib/sqlalchemy/sql/expression.py
index 2341cf79c..c9ef37c8b 100644
--- a/lib/sqlalchemy/sql/expression.py
+++ b/lib/sqlalchemy/sql/expression.py
@@ -1843,7 +1843,8 @@ class FromClause(Selectable):
         target_set = column.proxy_set
         cols = self.c
         for c in cols:
-            i = c.proxy_set.intersection(target_set)
+            i = target_set.intersection(itertools.chain(*[p._cloned_set for p in c.proxy_set]))
+
             if i and \
                 (not require_embedded or c.proxy_set.issuperset(target_set)):
                 
diff --git a/test/sql/test_selectable.py b/test/sql/test_selectable.py
index b0501c913..d1fd01141 100644
--- a/test/sql/test_selectable.py
+++ b/test/sql/test_selectable.py
@@ -57,7 +57,20 @@ class SelectableTest(TestBase, AssertsExecutionResults):
         # test alias of the join
         j2 = jjj.alias('foo')
         assert j2.corresponding_column(table1.c.col1) is j2.c.table1_col1
+    
+    def test_against_cloned_non_table(self):
+        # test that corresponding column digs across
+        # clone boundaries with anonymous labeled elements
+        col = func.count().label('foo')
+        sel = select([col])
+        
+        sel2 = visitors.ReplacingCloningVisitor().traverse(sel)
+        assert sel2.corresponding_column(col) is sel2.c.foo
 
+        sel3 = visitors.ReplacingCloningVisitor().traverse(sel2)
+        assert sel3.corresponding_column(col) is sel3.c.foo
+
+        
     def test_select_on_table(self):
         sel = select([table1, table2], use_labels=True)
         assert sel.corresponding_column(table1.c.col1) is sel.c.table1_col1