Fixed #20584 -- Fixed memcached's get_many() with single-use iterators.

Thanks Guyon Morée for the report.

1 files changed, 3 insertions, 6 deletions

diff --git a/django/core/cache/backends/memcached.py b/django/core/cache/backends/memcached.py
index 1c8066ba03..bb27cb53bb 100644
--- a/django/core/cache/backends/memcached.py
+++ b/django/core/cache/backends/memcached.py
@@ -84,12 +84,9 @@ class BaseMemcachedCache(BaseCache):
         self._cache.delete(key)
 
     def get_many(self, keys, version=None):
-        new_keys = [self.make_key(x, version=version) for x in keys]
-        ret = self._cache.get_multi(new_keys)
-        if ret:
-            m = dict(zip(new_keys, keys))
-            return {m[k]: v for k, v in ret.items()}
-        return ret
+        key_map = {self.make_key(key, version=version): key for key in keys}
+        ret = self._cache.get_multi(key_map.keys())
+        return {key_map[k]: v for k, v in ret.items()}
 
     def close(self, **kwargs):
         # Many clients don't clean up connections properly.