Return error when trying to update a stream with a source with a bad …

…subject transform (#5574)

In some cases a bad subject transform could still pass the validation
test that is part of the config check when updating a stream config, and
no error would be returned. Now return an error when trying to update a
stream config with a source that has a bad subject transform that is not
caught by the subject transform destination check in the stream config
check.

Improves #5571

---------

Signed-off-by: Jean-Noël Moyne <jnmoyne@gmail.com>

server/jetstream_test.go

@@ -22755,5 +22755,6 @@ func TestJetStreamBadSubjectMappingStream(t *testing.T) {
 			},
 		},
 	})
-	require_NoError(t, err)
+
+	require_Error(t, err, NewJSStreamUpdateError(errors.New("unable to get subject transform for source: invalid mapping destination: too many arguments passed to the function in {{wildcard(1)}}{{split(3,1)}}")))
 }

server/stream.go

@@ -1840,7 +1840,8 @@ 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.srv.Errorf("Unable to get subject transform for source: %v", err)
+								mset.mu.Unlock()
+								return fmt.Errorf("unable to get subject transform for source: %v", err)
 							}
 						}
 					}