From e03ef8a24bb60c491906488d51e8b4843919b54e Mon Sep 17 00:00:00 2001
From: Max Kellermann <mk@cm4all.com>
Date: Wed, 16 Aug 2023 17:39:28 +0200
Subject: [PATCH] istream/Chunked: copy the "fallback" flag in
 _FillBucketList()

Fixes stalled transfer because the HTTP server library never tried to
call Istream::Read().
---
 debian/changelog               | 1 +
 src/istream/ChunkedIstream.cxx | 6 +++++-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/debian/changelog b/debian/changelog
index f1ad797eb..2d0371193 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -2,6 +2,7 @@ cm4all-beng-proxy (18.0.31) unstable; urgency=low
 
   * io_uring: fix endless loop (18.0.30 regression)
   * io_uring: re-enable sendfile() (18.0.30 regression)
+  * http: fix stalled chunk transfer
 
  --   
 
diff --git a/src/istream/ChunkedIstream.cxx b/src/istream/ChunkedIstream.cxx
index 55e300ecd..3c97fc5d5 100644
--- a/src/istream/ChunkedIstream.cxx
+++ b/src/istream/ChunkedIstream.cxx
@@ -361,8 +361,12 @@ ChunkedIstream::_FillBucketList(IstreamBucketList &list)
 						       missing_from_current_chunk);
 		if (nbytes >= missing_from_current_chunk)
 			list.Push(AsBytes(list.HasMore() ? "\r\n"sv : "\r\n0\r\n\r\n"sv));
-	} else
+	} else {
 		list.SetMore();
+
+		if (sub.ShouldFallback())
+			list.EnableFallback();
+	}
 }
 
 Istream::ConsumeBucketResult