Clone internals for Select._correlate_except collection as well as _correlate

Fixed bug where use of :func:`.with_polymorphic` or other aliased construct
would not properly adapt when the aliased target were used as the
:meth:`.Select.correlate_except` target of a subquery used inside of a
:func:`.column_property`.  This required a fix to the clause adaption
mechanics to properly handle a selectable that shows up in the "correlate
except" list, in a similar manner as which occurs for selectables that show
up in the "correlate" list.  This is ultimately a fairly fundamental bug
that has lasted for a long time but it is hard to come across it.

Fixes: #4537
Change-Id: Ibb97d4eea18b3c452aad519dd14919bfb84d422f

1 files changed, 8 insertions, 0 deletions

diff --git a/lib/sqlalchemy/sql/selectable.py b/lib/sqlalchemy/sql/selectable.py
index cc6d2bcc5..d4528f0c3 100644
--- a/lib/sqlalchemy/sql/selectable.py
+++ b/lib/sqlalchemy/sql/selectable.py
@@ -3227,6 +3227,14 @@ class Select(HasPrefixes, HasSuffixes, GenerativeSelect):
         self._correlate = set(clone(f) for f in self._correlate).union(
             self._correlate
         )
+
+        # do something similar for _correlate_except - this is a more
+        # unusual case but same idea applies
+        if self._correlate_except:
+            self._correlate_except = set(
+                clone(f) for f in self._correlate_except
+            ).union(self._correlate_except)
+
         # 4. clone other things.   The difficulty here is that Column
         # objects are not actually cloned, and refer to their original
         # .table, resulting in the wrong "from" parent after a clone