Refs #24833 -- Forwardported some of "Fixed Case expressions with exclude()."

Partial forwardport of 469f1e362bb9670b174b37da9edd4631aff7badb from stable/1.8.x
as the issue was already fixed in master.

3 files changed, 21 insertions, 6 deletions

diff --git a/django/db/models/sql/query.py b/django/db/models/sql/query.py
index 88093d4541..55d083bdff 100644
--- a/django/db/models/sql/query.py
+++ b/django/db/models/sql/query.py
@@ -1026,9 +1026,9 @@ class Query(object):
         """
         lookup_splitted = lookup.split(LOOKUP_SEP)
         if self._annotations:
-            aggregate, aggregate_lookups = refs_expression(lookup_splitted, self.annotations)
-            if aggregate:
-                return aggregate_lookups, (), aggregate
+            expression, expression_lookups = refs_expression(lookup_splitted, self.annotations)
+            if expression:
+                return expression_lookups, (), expression
         _, field, _, lookup_parts = self.names_to_path(lookup_splitted, self.get_meta())
         field_parts = lookup_splitted[0:len(lookup_splitted) - len(lookup_parts)]
         if len(lookup_parts) == 0:
@@ -1145,7 +1145,7 @@ class Query(object):
         arg, value = filter_expr
         if not arg:
             raise FieldError("Cannot parse keyword query %r" % arg)
-        lookups, parts, reffed_aggregate = self.solve_lookup_type(arg)
+        lookups, parts, reffed_expression = self.solve_lookup_type(arg)
         if not allow_joins and len(parts) > 1:
             raise FieldError("Joined field references are not permitted in this query")
 
@@ -1154,8 +1154,8 @@ class Query(object):
         value, lookups, used_joins = self.prepare_lookup_value(value, lookups, can_reuse, allow_joins)
 
         clause = self.where_class()
-        if reffed_aggregate:
-            condition = self.build_lookup(lookups, reffed_aggregate, value)
+        if reffed_expression:
+            condition = self.build_lookup(lookups, reffed_expression, value)
             clause.add(condition, AND)
             return clause, []
 
diff --git a/docs/releases/1.8.3.txt b/docs/releases/1.8.3.txt
index 4f98027f7e..d544183445 100644
--- a/docs/releases/1.8.3.txt
+++ b/docs/releases/1.8.3.txt
@@ -50,3 +50,6 @@ Bugfixes
 
 * Fixed recording of applied status for squashed (replacement) migrations
   (:ticket:`24628`).
+
+* Fixed queryset annotations when using ``Case`` expressions with ``exclude()``
+  (:ticket:`24833`).
diff --git a/tests/expressions_case/tests.py b/tests/expressions_case/tests.py
index 6d35be8865..31ec88c7ec 100644
--- a/tests/expressions_case/tests.py
+++ b/tests/expressions_case/tests.py
@@ -240,6 +240,18 @@ class CaseExpressionTests(TestCase):
             transform=itemgetter('integer', 'max', 'test')
         )
 
+    def test_annotate_exclude(self):
+        self.assertQuerysetEqual(
+            CaseTestModel.objects.annotate(test=Case(
+                When(integer=1, then=Value('one')),
+                When(integer=2, then=Value('two')),
+                default=Value('other'),
+                output_field=models.CharField(),
+            )).exclude(test='other').order_by('pk'),
+            [(1, 'one'), (2, 'two'), (2, 'two')],
+            transform=attrgetter('integer', 'test')
+        )
+
     def test_combined_expression(self):
         self.assertQuerysetEqual(
             CaseTestModel.objects.annotate(