- fixed bug where selectable.corresponding_column(selectable.c.col)

would not return selectable.c.col, if the selectable is a join
of a table and another join involving the same table.  messed
up ORM decision making [ticket:593]

3 files changed, 14 insertions, 1 deletions

diff --git a/CHANGES b/CHANGES
index fa98520c8..f074b27f7 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,6 +1,10 @@
 - sql
     - long-identifier detection fixed to use > rather than >= for 
       max ident length [ticket:589]
+    - fixed bug where selectable.corresponding_column(selectable.c.col)
+      would not return selectable.c.col, if the selectable is a join
+      of a table and another join involving the same table.  messed
+      up ORM decision making [ticket:593]
 - mysql
     - added 'fields' to reserved words [ticket:590]
     
diff --git a/lib/sqlalchemy/sql.py b/lib/sqlalchemy/sql.py
index fb32c0f07..3a8a27d67 100644
--- a/lib/sqlalchemy/sql.py
+++ b/lib/sqlalchemy/sql.py
@@ -1670,7 +1670,9 @@ class FromClause(Selectable):
           it merely shares a common anscestor with one of
           the exported columns of this ``FromClause``.
         """
-
+        if column in self.c:
+            return column
+            
         if require_embedded and column not in util.Set(self._get_all_embedded_columns()):
             if not raiseerr:
                 return None
diff --git a/test/sql/selectable.py b/test/sql/selectable.py
index cd434a184..221d8430c 100755
--- a/test/sql/selectable.py
+++ b/test/sql/selectable.py
@@ -27,6 +27,13 @@ table2 = Table('table2', db,
 )

 

 class SelectableTest(testbase.AssertMixin):

+    def testjoinagainstjoin(self):

+        j  = outerjoin(table, table2, table.c.col1==table2.c.col2)

+        jj = select([ table.c.col1.label('bar_col1')],from_obj=[j]).alias('foo')

+        jjj = join(table, jj, table.c.col1==jj.c.bar_col1)

+        assert jjj.corresponding_column(jjj.c.table1_col1) is jjj.c.table1_col1

+        

+        

     def testtablealias(self):

         a = table.alias('a')