Fix NPE in trader chat

core/src/main/java/bisq/core/support/SupportManager.java

@@ -18,6 +18,7 @@
 package bisq.core.support;
 
 import bisq.core.btc.setup.WalletsSetup;
+import bisq.core.locale.Res;
 import bisq.core.support.messages.ChatMessage;
 import bisq.core.support.messages.SupportMessage;
 
@@ -191,7 +192,10 @@ private void onAckMessage(AckMessage ackMessage) {
     public ChatMessage sendChatMessage(ChatMessage message) {
         NodeAddress peersNodeAddress = getPeerNodeAddress(message);
         PubKeyRing receiverPubKeyRing = getPeerPubKeyRing(message);
-        if (receiverPubKeyRing != null) {
+        if (peersNodeAddress == null || receiverPubKeyRing == null) {
+            UserThread.runAfter(() ->
+                message.setSendMessageError(Res.get("support.receiverNotKnown")), 1);
+        } else {
             log.info("Send {} to peer {}. tradeId={}, uid={}",
                     message.getClass().getSimpleName(), peersNodeAddress, message.getTradeId(), message.getUid());
 

core/src/main/java/bisq/core/support/SupportSession.java

@@ -46,7 +46,7 @@ public boolean isClient() {
 
     public abstract String getTradeId();
 
-    public abstract PubKeyRing getClientPubKeyRing();
+    public abstract int getClientId();
 
     public abstract ObservableList<ChatMessage> getObservableChatMessageList();
 

core/src/main/java/bisq/core/support/dispute/DisputeSession.java

@@ -57,9 +57,14 @@ public String getTradeId() {
     }
 
     @Override
-    public PubKeyRing getClientPubKeyRing() {
+    public int getClientId() {
         // Get pubKeyRing of trader. Arbitrator is considered server for the chat session
-        return dispute != null ? dispute.getTraderPubKeyRing() : null;
+        try {
+            return dispute.getTraderPubKeyRing().hashCode();
+        } catch (NullPointerException e) {
+            log.warn("Unable to get traderPubKeyRing from Dispute - {}", e.toString());
+        }
+        return 0;
     }
 
     @Override

core/src/main/java/bisq/core/support/traderchat/TradeChatSession.java

@@ -48,12 +48,15 @@ public String getTradeId() {
     }
 
     @Override
-    public PubKeyRing getClientPubKeyRing() {
+    public int getClientId() {
         // TODO remove that client-server concept for trade chat
         // Get pubKeyRing of taker. Maker is considered server for chat sessions
-        if (trade != null && trade.getContract() != null)
-            return trade.getContract().getTakerPubKeyRing();
-        return null;
+        try {
+            return trade.getContract().getTakerPubKeyRing().hashCode();
+        } catch (NullPointerException e) {
+            log.warn("Unable to get takerPubKeyRing from Trade Contract - {}", e.toString());
+        }
+        return 0;
     }
 
     @Override

core/src/main/resources/i18n/displayStrings.properties

@@ -1105,6 +1105,7 @@ support.noTickets=There are no open tickets
 support.sendingMessage=Sending Message...
 support.receiverNotOnline=Receiver is not online. Message is saved to their mailbox.
 support.sendMessageError=Sending message failed. Error: {0}
+support.receiverNotKnown=Receiver not known
 support.wrongVersion=The offer in that dispute has been created with an older version of Bisq.\n\
 You cannot close that dispute with your version of the application.\n\n\
 Please use an older version with protocol version {0}

desktop/src/main/java/bisq/desktop/main/shared/ChatView.java

@@ -648,7 +648,7 @@ private ChatMessage sendDisputeDirectMessage(String text, ArrayList<Attachment>
             ChatMessage message = new ChatMessage(
                     supportManager.getSupportType(),
                     supportSession.getTradeId(),
-                    supportSession.getClientPubKeyRing().hashCode(),
+                    supportSession.getClientId(),
                     supportSession.isClient(),
                     text,
                     supportManager.getMyAddress(),