From 7e5e40ff849c92e4c062bad28848b5bdbb8bdd80 Mon Sep 17 00:00:00 2001
From: Kai Mueller <15907922+kasium@users.noreply.github.com>
Date: Thu, 24 Jun 2021 11:57:20 -0400
Subject: Fix missing None handling of Table.prefixes

Fixed issue where passing ``None`` for the value of
:paramref:`_schema.Table.prefixes` would not store an empty list, but
rather the constant ``None``, which may be unexpected by third party
dialects. The issue is revealed by a usage in recent versions of Alembic
that are passing ``None`` for this value. Pull request courtesy Kai
Mueller.

Fixes: #6685
Closes: #6672
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/6672
Pull-request-sha: b79aca0ee4011b244978b35fed4c687ffbe56dc9

Change-Id: I758641c6fbde6f2607d074fecea7efa6728aeea0
---
 lib/sqlalchemy/sql/schema.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'lib/sqlalchemy')

diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py
index 484cdddc8..a8870f7f1 100644
--- a/lib/sqlalchemy/sql/schema.py
+++ b/lib/sqlalchemy/sql/schema.py
@@ -660,7 +660,7 @@ class Table(DialectKWArgs, SchemaItem, TableClause):
             for evt, fn in listeners:
                 event.listen(self, evt, fn)
 
-        self._prefixes = kwargs.pop("prefixes", [])
+        self._prefixes = kwargs.pop("prefixes", None) or []
 
         self._extra_kwargs(**kwargs)
 
-- 
cgit v1.2.1