From 6f8460a8212e2d8896c3317d38eb36474a63d91c Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sat, 10 May 2025 20:41:47 +0800
Subject: [PATCH] http3: keep datagram receive loop running on datagram for
 unknown stream (#5136)

---
 http3/conn.go      | 7 +++----
 http3/conn_test.go | 1 +
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/http3/conn.go b/http3/conn.go
index 1a9a410e7..cbbe4445d 100644
--- a/http3/conn.go
+++ b/http3/conn.go
@@ -308,11 +308,10 @@ func (c *connection) receiveDatagrams() error {
 		streamID := protocol.StreamID(4 * quarterStreamID)
 		c.streamMx.Lock()
 		dg, ok := c.streams[streamID]
-		if !ok {
-			c.streamMx.Unlock()
-			return nil
-		}
 		c.streamMx.Unlock()
+		if !ok {
+			continue
+		}
 		dg.enqueue(b[n:])
 	}
 }
diff --git a/http3/conn_test.go b/http3/conn_test.go
index 7eb338404..d97508de2 100644
--- a/http3/conn_test.go
+++ b/http3/conn_test.go
@@ -392,6 +392,7 @@ var _ = Describe("Connection", func() {
 				close(delivered)
 				return b, nil
 			})
+			qconn.EXPECT().ReceiveDatagram(gomock.Any()).Return(nil, errors.New("test done"))
 			go func() {
 				defer GinkgoRecover()
 				conn.handleUnidirectionalStreams(nil)