Fixed #34212 -- Made RedisCacheClient.incr() use write connection.

Co-authored-by: Sin-Woo Bang <sinwoobang@gmail.com>

django/core/cache/backends/redis.py

@@ -130,7 +130,7 @@ class RedisCacheClient:
         return bool(client.exists(key))
 
     def incr(self, key, delta):
-        client = self.get_client(key)
+        client = self.get_client(key, write=True)
         if not client.exists(key):
             raise ValueError("Key '%s' not found." % key)
         return client.incr(key, delta)

tests/cache/tests.py

@@ -1787,6 +1787,14 @@ class RedisCacheTests(BaseCacheTests, TestCase):
     def incr_decr_type_error(self):
         return self.lib.ResponseError
 
+    def test_incr_write_connection(self):
+        cache.set("number", 42)
+        with mock.patch(
+            "django.core.cache.backends.redis.RedisCacheClient.get_client"
+        ) as mocked_get_client:
+            cache.incr("number")
+            self.assertEqual(mocked_get_client.call_args.kwargs, {"write": True})
+
     def test_cache_client_class(self):
         self.assertIs(cache._class, RedisCacheClient)
         self.assertIsInstance(cache._cache, RedisCacheClient)