Fixed #33826 -- Fixed RedisCache.set_many()/delete_many() crash with an empty list.

django/core/cache/backends/redis.py

@@ -214,6 +214,8 @@ class RedisCache(BaseCache):
         return self._cache.incr(key, delta)
 
     def set_many(self, data, timeout=DEFAULT_TIMEOUT, version=None):
+        if not data:
+            return []
         safe_data = {}
         for key, value in data.items():
             key = self.make_and_validate_key(key, version=version)
@@ -222,6 +224,8 @@ class RedisCache(BaseCache):
         return []
 
     def delete_many(self, keys, version=None):
+        if not keys:
+            return
         safe_keys = [self.make_and_validate_key(key, version=version) for key in keys]
         self._cache.delete_many(safe_keys)
 

tests/cache/tests.py

@@ -577,6 +577,9 @@ class BaseCacheTests:
         self.assertIsNone(cache.get("key1"))
         self.assertIsNone(cache.get("key2"))
 
+    def test_set_many_empty_data(self):
+        self.assertEqual(cache.set_many({}), [])
+
     def test_delete_many(self):
         # Multiple keys can be deleted using delete_many
         cache.set_many({"key1": "spam", "key2": "eggs", "key3": "ham"})
@@ -585,6 +588,9 @@ class BaseCacheTests:
         self.assertIsNone(cache.get("key2"))
         self.assertEqual(cache.get("key3"), "ham")
 
+    def test_delete_many_no_keys(self):
+        self.assertIsNone(cache.delete_many([]))
+
     def test_clear(self):
         # The cache can be emptied using clear
         cache.set_many({"key1": "spam", "key2": "eggs"})