[4.2.x] Fixed #34428 -- Made ASGIStaticFilesHandler adapt response to async iterator.

Bug in 0bd2c0c9015b53c41394a1c0989afbfd94dc2830.
Backport of 02c356f2f3945b8075735d485c3cf48cad991011 from main

1 files changed, 9 insertions, 0 deletions

diff --git a/django/contrib/staticfiles/handlers.py b/django/contrib/staticfiles/handlers.py
index b7d9b5c18d..6343e048d9 100644
--- a/django/contrib/staticfiles/handlers.py
+++ b/django/contrib/staticfiles/handlers.py
@@ -103,4 +103,13 @@ class ASGIStaticFilesHandler(StaticFilesHandlerMixin, ASGIHandler):
     async def get_response_async(self, request):
         response = await super().get_response_async(request)
         response._resource_closers.append(request.close)
+        # FileResponse is not async compatible.
+        if response.streaming and not response.is_async:
+            _iterator = response.streaming_content
+
+            async def awrapper():
+                for part in await sync_to_async(list)(_iterator):
+                    yield part
+
+            response.streaming_content = awrapper()
         return response