From 8d645cb713e9376f10a37a27c4ac86fecf431d9d Mon Sep 17 00:00:00 2001
From: Audrius Masalskis <audrius@gigpro.com>
Date: Wed, 4 Mar 2026 10:29:12 +0200
Subject: [PATCH 1/3] Fix Subquery annotation detection in dnfs() for Django
 6.0+

Django 6.0 resolves Subquery annotations into raw Query objects
in qs.query.annotations. The existing isinstance(q, Subquery)
check misses these, causing cross-table Subquery dependencies
to be invisible to cache invalidation.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 cacheops/tree.py | 11 ++++++++---
 tests/tests.py   | 24 ++++++++++++++++++++++++
 2 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/cacheops/tree.py b/cacheops/tree.py
index 6334ac73..19d23154 100644
--- a/cacheops/tree.py
+++ b/cacheops/tree.py
@@ -159,9 +159,14 @@ def table_for(alias):
 
     # Add any subqueries used for annotation
     if qs.query.annotations:
-        subqueries = (query_dnf(getattr(q, 'query', None))
-                      for q in qs.query.annotations.values() if isinstance(q, Subquery))
-        dnfs_.update(join_with(lcat, subqueries))
+        sub_dnfs = []
+        for q in qs.query.annotations.values():
+            if isinstance(q, Subquery):
+                sub_dnfs.append(query_dnf(getattr(q, 'query', None)))
+            elif isinstance(q, Query):
+                sub_dnfs.append(query_dnf(q))
+        if sub_dnfs:
+            dnfs_.update(join_with(lcat, sub_dnfs))
 
     return dnfs_
 
diff --git a/tests/tests.py b/tests/tests.py
index 33f35945..0279d4d1 100644
--- a/tests/tests.py
+++ b/tests/tests.py
@@ -643,6 +643,30 @@ def test_365(self):
         categories = Category.objects.cache().annotate(newest_post=Subquery(newest_post[:1]))
         self.assertEqual(categories[0].newest_post, post.pk)
 
+    def test_366(self):
+        """
+        Check that dnfs() detects table dependencies from
+        Subquery annotations.
+
+        Django 6.0+ resolves Subquery into raw Query objects
+        in qs.query.annotations, so this verifies detection
+        works regardless of how the annotation is stored.
+        """
+        from cacheops.tree import dnfs
+
+        newest_post = Post.objects.filter(
+            category=OuterRef('pk')
+        ).order_by('-pk').values('pk')
+        qs = Category.objects.cache().annotate(
+            newest_post=Subquery(newest_post[:1])
+        )
+        result = dnfs(qs)
+
+        self.assertEqual(result, {
+            Category._meta.db_table: [{}],
+            Post._meta.db_table: [{}],
+        })
+
     @unittest.skipIf(platform.python_implementation() == "PyPy", "dill doesn't do that in PyPy")
     def test_385(self):
         Client.objects.create(name='Client Name')

From aa68dbc310d792ad3bcf63d8656fe3f4a28bc545 Mon Sep 17 00:00:00 2001
From: Audrius Masalskis <audrius@gigpro.com>
Date: Wed, 4 Mar 2026 10:56:11 +0200
Subject: [PATCH 2/3] Tweak the new test to make it more compact

---
 tests/tests.py | 24 ++++++------------------
 1 file changed, 6 insertions(+), 18 deletions(-)

diff --git a/tests/tests.py b/tests/tests.py
index 0279d4d1..f99f8e26 100644
--- a/tests/tests.py
+++ b/tests/tests.py
@@ -645,27 +645,15 @@ def test_365(self):
 
     def test_366(self):
         """
-        Check that dnfs() detects table dependencies from
-        Subquery annotations.
-
-        Django 6.0+ resolves Subquery into raw Query objects
-        in qs.query.annotations, so this verifies detection
-        works regardless of how the annotation is stored.
+        Check that dnfs() detects table dependencies from Subquery annotations.
+        Django 6.0+ resolves Subquery into raw Query objects in qs.query.annotations, so this
+        verifies detection works regardless of how the annotation is stored.
         """
         from cacheops.tree import dnfs
 
-        newest_post = Post.objects.filter(
-            category=OuterRef('pk')
-        ).order_by('-pk').values('pk')
-        qs = Category.objects.cache().annotate(
-            newest_post=Subquery(newest_post[:1])
-        )
-        result = dnfs(qs)
-
-        self.assertEqual(result, {
-            Category._meta.db_table: [{}],
-            Post._meta.db_table: [{}],
-        })
+        newest_post = Post.objects.filter(category=OuterRef('pk')).order_by('-pk').values('pk')
+        qs = Category.objects.cache().annotate(newest_post=Subquery(newest_post[:1]))
+        self.assertEqual(dnfs(qs), {Category._meta.db_table: [{}], Post._meta.db_table: [{}]})
 
     @unittest.skipIf(platform.python_implementation() == "PyPy", "dill doesn't do that in PyPy")
     def test_385(self):

From 98eb0c882e0aab79d242812f0450f0beec303939 Mon Sep 17 00:00:00 2001
From: Audrius Masalskis <audrius@gigpro.com>
Date: Wed, 4 Mar 2026 11:03:19 +0200
Subject: [PATCH 3/3] Address feddback

---
 cacheops/tree.py | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/cacheops/tree.py b/cacheops/tree.py
index 19d23154..de2638d8 100644
--- a/cacheops/tree.py
+++ b/cacheops/tree.py
@@ -165,8 +165,7 @@ def table_for(alias):
                 sub_dnfs.append(query_dnf(getattr(q, 'query', None)))
             elif isinstance(q, Query):
                 sub_dnfs.append(query_dnf(q))
-        if sub_dnfs:
-            dnfs_.update(join_with(lcat, sub_dnfs))
+        dnfs_.update(join_with(lcat, sub_dnfs) or {})
 
     return dnfs_