[5.2.x] Fixed #36117 -- Raised ValueError when providing composite expressions to case / when.

Remove redundant Case and When.resolve_expression to delegate composite
expression support to BaseExpression.

Thanks Jacob Tyler Walls for the report and test.

Backport of 00c690efbc0b10f67924687f24a7b30397bf47d9 from main.

1 files changed, 18 insertions, 1 deletions

diff --git a/tests/composite_pk/test_filter.py b/tests/composite_pk/test_filter.py
index aa2d9ebe36..fe942b9e5b 100644
--- a/tests/composite_pk/test_filter.py
+++ b/tests/composite_pk/test_filter.py
@@ -1,4 +1,13 @@
-from django.db.models import F, FilteredRelation, OuterRef, Q, Subquery, TextField
+from django.db.models import (
+    Case,
+    F,
+    FilteredRelation,
+    OuterRef,
+    Q,
+    Subquery,
+    TextField,
+    When,
+)
 from django.db.models.functions import Cast
 from django.db.models.lookups import Exact
 from django.test import TestCase
@@ -409,6 +418,14 @@ class CompositePKFilterTests(TestCase):
         with self.assertRaisesMessage(ValueError, msg):
             Comment.objects.filter(text__gt=Cast(F("pk"), TextField())).count()
 
+    def test_filter_case_when(self):
+        msg = "When expression does not support composite primary keys."
+        with self.assertRaisesMessage(ValueError, msg):
+            Comment.objects.filter(text=Case(When(text="", then="pk")))
+        msg = "Case expression does not support composite primary keys."
+        with self.assertRaisesMessage(ValueError, msg):
+            Comment.objects.filter(text=Case(When(text="", then="text"), default="pk"))
+
     def test_outer_ref_pk(self):
         subquery = Subquery(Comment.objects.filter(pk=OuterRef("pk")).values("id"))
         tests = [