- rework ColumnCollection to no longer persist "all_col_set"; we don't

need this collection except in the extend/update uses where we
create it ad-hoc.  simplifies pickling.  Compatibility with 1.0
should be OK as ColumnColleciton uses __getstate__ in any case
and the __setstate__ contract hasn't changed.
- Fixed bug in :class:`.Table` metadata construct which appeared
around the 0.9 series where adding columns to a :class:`.Table`
that was unpickled would fail to correctly establish the
:class:`.Column` within the 'c' collection, leading to issues in
areas such as ORM configuration.   This could impact use cases such
as ``extend_existing`` and others.  fixes #3632

1 files changed, 19 insertions, 0 deletions

diff --git a/test/sql/test_metadata.py b/test/sql/test_metadata.py
index 47ecf5a9b..050929d3d 100644
--- a/test/sql/test_metadata.py
+++ b/test/sql/test_metadata.py
@@ -1258,6 +1258,25 @@ class TableTest(fixtures.TestBase, AssertsCompiledSQL):
             assign2
         )
 
+    def test_c_mutate_after_unpickle(self):
+        m = MetaData()
+
+        y = Column('y', Integer)
+        t1 = Table('t', m, Column('x', Integer), y)
+
+        t2 = pickle.loads(pickle.dumps(t1))
+        z = Column('z', Integer)
+        g = Column('g', Integer)
+        t2.append_column(z)
+
+        is_(t1.c.contains_column(y), True)
+        is_(t2.c.contains_column(y), False)
+        y2 = t2.c.y
+        is_(t2.c.contains_column(y2), True)
+
+        is_(t2.c.contains_column(z), True)
+        is_(t2.c.contains_column(g), False)
+
     def test_autoincrement_replace(self):
         m = MetaData()