Say why a connection ended, and mark the channel we are in subscribed

- A failed connect keeps its reason in the status instead of a bare
  "Disconnected", as does a disconnect the server gave a reason for.
- The server never announces the subscription to the channel we start
  out in, although it keeps us subscribed after we leave it, so the
  channel we enter counts as subscribed.
- A client connecting or leaving the server is logged as that, not as
  switching from or to "channel #0": the server gives both the same
  reason, only with no channel on one side.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

ts3-client/core/src/main/java/com/ts3client/net/ConnectionEventHandler.java

@@ -81,6 +81,7 @@ final class ConnectionEventHandler implements TS3Listener {
             int from = c.channelId;
             c.channelId = e.getTargetChannelId();
             if (e.getClientId() == conn.getSelfClientId()) {
+                conn.getModel().enteredChannel(e.getTargetChannelId());
                 announceOwnMove(safeInt(e, "reasonid"), e);
                 logOwnMove(e, from, e.getTargetChannelId());
             } else if (!c.isQuery()) {
@@ -95,7 +96,10 @@ final class ConnectionEventHandler implements TS3Listener {
     private void logClientEntered(ClientJoinEvent e) {
         String name = conn.clientLink(e.getClientId(),
                 TeamspeakConnection.orEmpty(e.getUniqueClientIdentifier()), e.getClientNickname());
-        switch (safeInt(e, "reasonid")) {
+        // A client connecting also comes with "switched", only from no channel at all.
+        int reason = safeInt(e, "reasonid");
+        if (reason == REASON_SWITCHED && e.getClientFromId() == 0) reason = -1;
+        switch (reason) {
             case REASON_MOVED:
                 conn.log(name + " appears, coming from channel \"" + conn.channelLink(e.getClientFromId()) + "\"");
                 break;
@@ -116,7 +120,10 @@ final class ConnectionEventHandler implements TS3Listener {
     private void logClientLeft(ClientLeaveEvent e, String name) {
         String reasonMsg = TeamspeakConnection.orEmpty(e.get("reasonmsg"));
         String suffix = reasonMsg.isEmpty() ? "" : " (" + reasonMsg + ")";
-        switch (safeInt(e, "reasonid")) {
+        int reason = safeInt(e, "reasonid");
+        // A client leaving the server may also come with "switched", only to no channel at all.
+        if (reason == REASON_SWITCHED && e.getClientTargetId() == 0) reason = -1;
+        switch (reason) {
             case REASON_TIMEOUT:
                 conn.log(name + " dropped (ping timeout)");
                 break;

ts3-client/core/src/main/java/com/ts3client/net/ServerModel.java

@@ -229,6 +229,16 @@ public final class ServerModel {
         return channels.get(id);
     }
 
+    /**
+     * Marks the channel we are in as subscribed. The server tells us about it along with
+     * everything else there, but never announces the subscription for the channel we
+     * start out in, although it stays subscribed after we leave it.
+     */
+    public synchronized void enteredChannel(int id) {
+        ChannelNode channel = channels.get(id);
+        if (channel != null) channel.subscribed = true;
+    }
+
     public synchronized void removeChannel(int id) {
         ChannelNode c = channels.remove(id);
         if (c == null) return;

ts3-client/core/src/main/java/com/ts3client/net/TeamspeakConnection.java

@@ -332,7 +332,10 @@ public final class TeamspeakConnection implements TS3Listener {
             // handshake carries, i.e. before our id was known here, so it has to be
             // marked once it is.
             ClientEntry ourselves = model.getClient(selfClientId);
-            if (ourselves != null) ourselves.self = true;
+            if (ourselves != null) {
+                ourselves.self = true;
+                model.enteredChannel(ourselves.channelId);
+            }
             fileTransfers = new FileTransferManager(client, () -> serverHost);
             client.setMicrophone(microphone);
             icons.retryFailed();
@@ -360,12 +363,13 @@ public final class TeamspeakConnection implements TS3Listener {
             // connect has set up in the meantime.
             if (connectAttempt != attempt) return;
             connected = false;
-            ui.onError("Connection failed: " + rootMessage(e) + versionHint(e));
+            String failure = "Connection failed: " + rootMessage(e) + versionHint(e);
+            ui.onError(failure);
             safeCleanup();
             // Report the failed attempt as a disconnect too, so the UI leaves the
-            // "connecting" state and the tab becomes reusable.
+            // "connecting" state and the tab becomes reusable. The status keeps saying why.
             ui.onDisconnected("connection failed");
-            ui.onStatus("Disconnected");
+            ui.onStatus(failure);
         }
     }
 
@@ -1370,8 +1374,9 @@ public final class TeamspeakConnection implements TS3Listener {
         connected = false;
         safeCleanup();
         announceDisconnect(false);
-        ui.onDisconnected(orEmpty(e.getReasonMessage()));
+        String reason = orEmpty(e.getReasonMessage());
-        ui.onStatus("Disconnected");
+        ui.onDisconnected(reason);
+        ui.onStatus(reason.isEmpty() ? "Disconnected" : "Disconnected: " + reason);
     }
 
     // ---- sound notifications ----