From ed0dfaefed5fda6222cc43a70b79d50adef5a1f4 Mon Sep 17 00:00:00 2001
From: Derek Collison <derek@nats.io>
Date: Thu, 20 Jun 2024 17:11:55 +0800
Subject: [PATCH] Do not unlock here, will panic server.

Signed-off-by: Derek Collison <derek@nats.io>
---
 server/jetstream_test.go | 29 +++++++++++++++++++++++++++++
 server/stream.go         |  1 -
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/server/jetstream_test.go b/server/jetstream_test.go
index 348299accb0..49adf5c489e 100644
--- a/server/jetstream_test.go
+++ b/server/jetstream_test.go
@@ -23733,3 +23733,32 @@ func TestJetStreamAuditStreams(t *testing.T) {
 	})
 	require_NoError(t, err)
 }
+
+// https://github.com/nats-io/nats-server/issues/5570
+func TestJetStreamBadSubjectMappingStream(t *testing.T) {
+	s := RunBasicJetStreamServer(t)
+	defer s.Shutdown()
+
+	// Client for API requests.
+	nc, js := jsClientConnect(t, s)
+	defer nc.Close()
+
+	_, err := js.AddStream(&nats.StreamConfig{Name: "test"})
+	require_NoError(t, err)
+
+	_, err = js.UpdateStream(&nats.StreamConfig{
+		Name: "test",
+		Sources: []*nats.StreamSource{
+			{
+				Name: "mapping",
+				SubjectTransforms: []nats.SubjectTransformConfig{
+					{
+						Source:      "events.*",
+						Destination: "events.{{wildcard(1)}}{{split(3,1)}}",
+					},
+				},
+			},
+		},
+	})
+	require_NoError(t, err)
+}
diff --git a/server/stream.go b/server/stream.go
index 690c87495cc..65e0a574605 100644
--- a/server/stream.go
+++ b/server/stream.go
@@ -1846,7 +1846,6 @@ func (mset *stream) updateWithAdvisory(config *StreamConfig, sendAdvisory bool)
 							var err error
 							si.trs[i], err = NewSubjectTransform(s.SubjectTransforms[i].Source, s.SubjectTransforms[i].Destination)
 							if err != nil {
-								mset.mu.Unlock()
 								mset.srv.Errorf("Unable to get subject transform for source: %v", err)
 							}
 						}