From af4f079bf5ae5bec16868da61c4858b1c68bf672 Mon Sep 17 00:00:00 2001
From: Patrick Cloke <patrickc@matrix.org>
Date: Fri, 17 Jul 2020 12:33:19 -0400
Subject: [PATCH] Guard against improper implementations.

---
 synapse/rest/media/v1/media_storage.py | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/synapse/rest/media/v1/media_storage.py b/synapse/rest/media/v1/media_storage.py
index c943baacfb37..87fe06cf56f6 100644
--- a/synapse/rest/media/v1/media_storage.py
+++ b/synapse/rest/media/v1/media_storage.py
@@ -14,6 +14,7 @@
 # limitations under the License.
 
 import contextlib
+import inspect
 import logging
 import os
 import shutil
@@ -104,7 +105,11 @@ def store_into_file(self, file_info):
 
         async def finish():
             for provider in self.storage_providers:
-                await provider.store_file(path, file_info)
+                # store_file is supposed to return an Awaitable or Deferred, but
+                # guard against improper implementations.
+                result = provider.store_file(path, file_info)
+                if inspect.isawaitable(result) or isinstance(result, defer.Deferred):
+                    await result
 
             finished_called[0] = True