Refs #27849 -- Fixed filtered aggregates crash on filters that match everything.

django/db/models/aggregates.py

@@ -105,6 +105,7 @@ class Aggregate(Func):
         if self.filter:
             if connection.features.supports_aggregate_filter_clause:
                 filter_sql, filter_params = self.filter.as_sql(compiler, connection)
+                if filter_sql:
                     template = self.filter_template % extra_context.get(
                         "template", self.template
                     )

tests/aggregation/test_filter_argument.py

@@ -205,3 +205,16 @@ class FilteredAggregateTests(TestCase):
             max_rating=Max("rating", filter=Q(rating__in=[]))
         )
         self.assertEqual(aggregate, {"max_rating": None})
+
+    def test_filtered_aggregate_full_condition(self):
+        book = Book.objects.annotate(
+            authors_count=Count(
+                "authors",
+                filter=~Q(authors__in=[]),
+            ),
+        ).get(pk=self.b1.pk)
+        self.assertEqual(book.authors_count, 2)
+        aggregate = Book.objects.aggregate(
+            max_rating=Max("rating", filter=~Q(rating__in=[]))
+        )
+        self.assertEqual(aggregate, {"max_rating": 4.5})