From 7a67b065d7e5653f3af1cbd28882d33d2a088b02 Mon Sep 17 00:00:00 2001
From: Simon Charette <charette.s@gmail.com>
Date: Mon, 17 Jul 2023 12:51:54 -0400
Subject: [PATCH] [4.2.x] Fixed #34717 -- Fixed QuerySet.aggregate() crash when
 referencing window functions.

Regression in 59bea9efd2768102fc9d3aedda469502c218e9b7.

Refs #28477.

Thanks younes-chaoui for the report.

Backport of 68912e4f6f84f21322f92a2c7b6c77f68f91b9c9 from main
---
 django/db/models/sql/query.py |  6 ++++++
 docs/releases/4.2.4.txt       |  4 +++-
 tests/aggregation/tests.py    | 21 +++++++++++++++++++++
 3 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/django/db/models/sql/query.py b/django/db/models/sql/query.py
index 97c0bb4a08..c9656cc450 100644
--- a/django/db/models/sql/query.py
+++ b/django/db/models/sql/query.py
@@ -390,6 +390,7 @@ class Query(BaseExpression):
         # Store annotation mask prior to temporarily adding aggregations for
         # resolving purpose to facilitate their subsequent removal.
         refs_subquery = False
+        refs_window = False
         replacements = {}
         annotation_select_mask = self.annotation_select_mask
         for alias, aggregate_expr in aggregate_exprs.items():
@@ -406,6 +407,10 @@ class Query(BaseExpression):
                 getattr(self.annotations[ref], "subquery", False)
                 for ref in aggregate.get_refs()
             )
+            refs_window |= any(
+                getattr(self.annotations[ref], "contains_over_clause", True)
+                for ref in aggregate.get_refs()
+            )
             aggregate = aggregate.replace_expressions(replacements)
             self.annotations[alias] = aggregate
             replacements[Ref(alias, aggregate)] = aggregate
@@ -438,6 +443,7 @@ class Query(BaseExpression):
             or self.is_sliced
             or has_existing_aggregation
             or refs_subquery
+            or refs_window
             or qualify
             or self.distinct
             or self.combinator
diff --git a/docs/releases/4.2.4.txt b/docs/releases/4.2.4.txt
index e8fd225516..3921dd9b3e 100644
--- a/docs/releases/4.2.4.txt
+++ b/docs/releases/4.2.4.txt
@@ -9,4 +9,6 @@ Django 4.2.4 fixes several bugs in 4.2.3.
 Bugfixes
 ========
 
-* ...
+* Fixed a regression in Django 4.2 that caused a crash of
+  ``QuerySet.aggregate()`` with aggregates referencing window functions
+  (:ticket:`34717`).
diff --git a/tests/aggregation/tests.py b/tests/aggregation/tests.py
index 366b8434e5..db69246952 100644
--- a/tests/aggregation/tests.py
+++ b/tests/aggregation/tests.py
@@ -28,6 +28,7 @@ from django.db.models import (
     Value,
     Variance,
     When,
+    Window,
 )
 from django.db.models.expressions import Func, RawSQL
 from django.db.models.functions import (
@@ -2207,3 +2208,23 @@ class AggregateAnnotationPruningTests(TestCase):
         sql = ctx.captured_queries[0]["sql"].lower()
         self.assertEqual(sql.count("select"), 3, "Subquery wrapping required")
         self.assertEqual(aggregate, {"sum_total_books": 3})
+
+    @skipUnlessDBFeature("supports_over_clause")
+    def test_referenced_window_requires_wrapping(self):
+        total_books_qs = Book.objects.annotate(
+            avg_publisher_pages=Coalesce(
+                Window(Avg("pages"), partition_by=F("publisher")),
+                0.0,
+            )
+        )
+        with self.assertNumQueries(1) as ctx:
+            aggregate = total_books_qs.aggregate(
+                sum_avg_publisher_pages=Sum("avg_publisher_pages"),
+                books_count=Count("id"),
+            )
+        sql = ctx.captured_queries[0]["sql"].lower()
+        self.assertEqual(sql.count("select"), 2, "Subquery wrapping required")
+        self.assertEqual(
+            aggregate,
+            {"sum_avg_publisher_pages": 1100.0, "books_count": 2},
+        )