Preserve stack trace for CancelledSubscriptionException

core/src/main/java/com/linecorp/armeria/common/stream/CancellableStreamMessage.java

@@ -47,8 +47,6 @@ abstract class CancellableStreamMessage<T> extends AggregationSupport implements
     static final Logger logger = LoggerFactory.getLogger(CancellableStreamMessage.class);
 
     static final CloseEvent SUCCESSFUL_CLOSE = new CloseEvent(null);
-    static final CloseEvent CANCELLED_CLOSE = new CloseEvent(CancelledSubscriptionException.INSTANCE);
-    static final CloseEvent ABORTED_CLOSE = new CloseEvent(AbortedStreamException.INSTANCE);
 
     private final CompletableFuture<Void> completionFuture = new EventLoopCheckingFuture<>();
 
@@ -134,17 +132,10 @@ final T prepareObjectForNotification(T o, boolean withPooledObjects) {
     }
 
     /**
-     * Returns newly created {@link CloseEvent} if the specified {@link Throwable} is not an instance of
-     * {@link CancelledSubscriptionException#INSTANCE} or {@link AbortedStreamException#INSTANCE}.
+     * Returns newly created {@link CloseEvent} with the cause.
      */
     static CloseEvent newCloseEvent(Throwable cause) {
-        if (cause == CancelledSubscriptionException.INSTANCE) {
-            return CANCELLED_CLOSE;
-        } else if (cause == AbortedStreamException.INSTANCE) {
-            return ABORTED_CLOSE;
-        } else {
-            return new CloseEvent(cause);
-        }
+        return new CloseEvent(cause);
     }
 
     static final class SubscriptionImpl implements Subscription {

core/src/main/java/com/linecorp/armeria/common/stream/DefaultStreamMessage.java

@@ -290,10 +290,10 @@ private void doRequest(long n) {
     final void cancel() {
         if (setState(State.OPEN, State.CLEANUP) || setState(State.CLOSED, State.CLEANUP)) {
             // It the state was CLOSED, close() or close(cause) has been called before cancel() or abort()
-            // is called. We just ignore the previously pushed event and deal with CANCELLED_CLOSE.
+            // is called. We just ignore the previously pushed event and deal with cancelled close event.
             final SubscriptionImpl subscription = this.subscription;
             assert subscription != null;
-            notifySubscriberOfCloseEvent(subscription, CANCELLED_CLOSE);
+            notifySubscriberOfCloseEvent(subscription, new CloseEvent(CancelledSubscriptionException.get()));
         }
     }