ActivityPub: fix UOE

1 files changed, 5 insertions, 1 deletions

diff --git a/juick-server/src/main/java/com/juick/server/ActivityPubManager.java b/juick-server/src/main/java/com/juick/server/ActivityPubManager.java
index 1ffd376b..41dd52eb 100644
--- a/juick-server/src/main/java/com/juick/server/ActivityPubManager.java
+++ b/juick-server/src/main/java/com/juick/server/ActivityPubManager.java
@@ -31,9 +31,11 @@ import java.io.IOException;
 import java.io.StringWriter;
 import java.io.Writer;
 import java.net.URI;
+import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
@@ -139,7 +141,9 @@ public class ActivityPubManager implements ActivityListener, NotificationListene
         if (MessageUtils.isReply(msg) && msg.getTo().getUri().toASCIIString().length() > 0) {
             String replier = msg.getTo().getUri().toASCIIString();
             subscribers.add(replier);
-            note.getCc().add(replier);
+            List<String> cc = new ArrayList<>(note.getCc());
+            cc.add(replier);
+            note.setCc(cc);
         }
         subscribers.forEach(acct -> {
             Optional<Context> context = signatureManager.getContext(URI.create(acct));