From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Thu, 27 Jun 2024 22:17:47 +0000 (-0400)
Subject: cache key share; support correct traverse of 'of'
X-Git-Tag: rel_1_4_53~9
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=9f9d99928e6efb921c4dcd5febf810632c5521e8;p=thirdparty%2Fsqlalchemy%2Fsqlalchemy.git

cache key share; support correct traverse of 'of'

Fixed caching issue where the
:paramref:`_sql.Select.with_for_update.key_share` element of
:meth:`_sql.Select.with_for_update` was not considered as part of the cache
key, leading to incorrect caching if different variations of this parameter
were used with an otherwise identical statement.

Also repairs a traversal issue where the ``of`` element of
``ForUpdateArg`` when set to ``None`` cannot be compared against a
non-None element because the traversal defines it as a clauselist.
Traversal in this case is adjusted to accommodate for this case so that
we dont need to create a risky-to-backport change to ``ForUpdateArg``
itself.

Fixes: #11544
Change-Id: Ie8a50716df06977af58b0c22a8c10e1b64d972b9
(cherry picked from commit 6d2f43e14f2fe25cdc811355b7bd6d11f8eee381)
(cherry picked from commit 522baa306fc788cf02acf29bf08e86a431a7050e)
---

diff --git a/lib/sqlalchemy/sql/selectable.py b/lib/sqlalchemy/sql/selectable.py
index 95d2fdf245..7536665a6e 100644
--- a/lib/sqlalchemy/sql/selectable.py
+++ b/lib/sqlalchemy/sql/selectable.py
@@ -2831,6 +2831,7 @@ class ForUpdateArg(ClauseElement):
         ("nowait", InternalTraversal.dp_boolean),
         ("read", InternalTraversal.dp_boolean),
         ("skip_locked", InternalTraversal.dp_boolean),
+        ("key_share", InternalTraversal.dp_boolean),
     ]
 
     @classmethod
diff --git a/lib/sqlalchemy/sql/traversals.py b/lib/sqlalchemy/sql/traversals.py
index 41b960c9c3..eb4913d7c3 100644
--- a/lib/sqlalchemy/sql/traversals.py
+++ b/lib/sqlalchemy/sql/traversals.py
@@ -1159,6 +1159,8 @@ class TraversalComparatorStrategy(InternalTraversal, util.MemoizedSlots):
                         return False
                     else:
                         continue
+                elif right_child is None:
+                    return False
 
                 comparison = dispatch(
                     left_attrname, left, left_child, right, right_child, **kw
diff --git a/test/sql/test_compare.py b/test/sql/test_compare.py
index 0a7f0d4114..3e13174f79 100644
--- a/test/sql/test_compare.py
+++ b/test/sql/test_compare.py
@@ -472,6 +472,21 @@ class CoreFixtures(object):
             select(table_a.c.a)
             .where(table_a.c.b == 5)
             .with_for_update(nowait=True),
+            select(table_a.c.a)
+            .where(table_a.c.b == 5)
+            .with_for_update(nowait=True, skip_locked=True),
+            select(table_a.c.a)
+            .where(table_a.c.b == 5)
+            .with_for_update(nowait=True, read=True),
+            select(table_a.c.a)
+            .where(table_a.c.b == 5)
+            .with_for_update(of=table_a.c.a),
+            select(table_a.c.a)
+            .where(table_a.c.b == 5)
+            .with_for_update(of=table_a.c.b),
+            select(table_a.c.a)
+            .where(table_a.c.b == 5)
+            .with_for_update(nowait=True, key_share=True),
             select(table_a.c.a).where(table_a.c.b == 5).correlate(table_b),
             select(table_a.c.a)
             .where(table_a.c.b == 5)