SYN-229: Include Content-Length when downloading files

1 files changed, 10 insertions, 2 deletions

diff --git a/synapse/media/v1/base_resource.py b/synapse/media/v1/base_resource.py
index 2f5440ab64..38e01970c0 100644
--- a/synapse/media/v1/base_resource.py
+++ b/synapse/media/v1/base_resource.py
@@ -201,7 +201,8 @@ class BaseMediaResource(Resource):
         defer.returnValue(media_info)
 
     @defer.inlineCallbacks
-    def _respond_with_file(self, request, media_type, file_path):
+    def _respond_with_file(self, request, media_type, file_path,
+                           file_size=None):
         logger.debug("Responding with %r", file_path)
 
         if os.path.isfile(file_path):
@@ -215,13 +216,20 @@ class BaseMediaResource(Resource):
             request.setHeader(
                 b"Cache-Control", b"public,max-age=86400,s-maxage=86400"
             )
+            if file_size is None:
+                stat = os.stat(file_path)
+                file_size = stat.st_size
+
+            request.setHeader(
+                b"Content-Length", b"%d" % (file_size,)
+            )
 
             with open(file_path, "rb") as f:
                 yield FileSender().beginFileTransfer(f, request)
 
             request.finish()
         else:
-            self._respond_404()
+            self._respond_404(request)
 
     def _get_thumbnail_requirements(self, media_type):
         if media_type == "image/jpeg":