Update ts3j: resend like the official client; clean up failed connects

- ts3j: native resend timing, INIT1 resends, one clientinitiv per handshake,
  non-blocking disconnect.
- Ignore errors from a connect attempt that has been superseded or cancelled.
- Show the whole cause chain in network error messages.
- -Dts3j.debug=true enables ts3j's protocol logging.
- Tests run with a throwaway user.home instead of the real profile.

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

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

@@ -105,6 +105,11 @@ public final class TeamspeakConnection implements TS3Listener {
     private ExecutorService eventExecutor;
 
     private volatile boolean connected;
+    /**
+     * The connect in progress. A disconnect clears it and a newer connect replaces it, which
+     * tells a superseded attempt that is still failing not to clean up after itself.
+     */
+    private volatile Object connectAttempt;
     private volatile int selfClientId = -1;
     /** Package-private: read directly by {@link ConnectionStatsCollector}. */
     volatile long connectedAtMs;
@@ -240,6 +245,8 @@ public final class TeamspeakConnection implements TS3Listener {
 
     private void doConnect(String address, int port, String nickname, String password, LocalIdentity withIdentity,
                            String channel, String channelPassword) {
+        Object attempt = new Object();
+        connectAttempt = attempt;
         try {
             identity = withIdentity;
             serverHost = address;
@@ -290,7 +297,7 @@ public final class TeamspeakConnection implements TS3Listener {
                 // A late packet dispatched after close() rejects on the shut-down
                 // command executor; harmless during teardown.
                 if (t instanceof java.util.concurrent.RejectedExecutionException) return;
-                ui.onError("Network error: " + rootMessage(t));
+                ui.onError("Network error: " + messageChain(t));
             });
 
             applyClientVersion();
@@ -331,6 +338,9 @@ public final class TeamspeakConnection implements TS3Listener {
             // Only captures if this connection holds the microphone.
             applyMicrophoneState();
         } catch (Exception e) {
+            // Whoever took over reports on their own; cleaning up here would tear down what a newer
+            // connect has set up in the meantime.
+            if (connectAttempt != attempt) return;
             connected = false;
             ui.onError("Connection failed: " + rootMessage(e) + versionHint(e));
             safeCleanup();
@@ -505,6 +515,7 @@ public final class TeamspeakConnection implements TS3Listener {
      * close) where the JVM must not exit before the leave notification is sent.
      */
     public void disconnectBlocking(String reason) {
+        connectAttempt = null;
         leaving = true;
         try {
             if (client != null) client.disconnect(reason);
@@ -1667,6 +1678,18 @@ public final class TeamspeakConnection implements TS3Listener {
         return s == null ? "" : s;
     }
 
+    /** Every message along the cause chain, outermost first: network errors are vague without context. */
+    private static String messageChain(Throwable t) {
+        StringBuilder chain = new StringBuilder();
+        for (Throwable c = t; c != null; c = c.getCause() == c ? null : c.getCause()) {
+            String m = c.getMessage();
+            if (m == null || chain.indexOf(m) >= 0) continue;
+            if (chain.length() > 0) chain.append(": ");
+            chain.append(m);
+        }
+        return chain.length() > 0 ? chain.toString() : t.getClass().getSimpleName();
+    }
+
     private static String rootMessage(Throwable t) {
         Throwable r = t;
         while (r.getCause() != null && r.getCause() != r) r = r.getCause();

ts3-client/pom.xml

@@ -34,6 +34,12 @@
                     <groupId>org.apache.maven.plugins</groupId>
                     <artifactId>maven-surefire-plugin</artifactId>
                     <version>${surefire.version}</version>
+                    <configuration>
+                        <!-- The stores resolve ~/.ts3jclient once per JVM; keep every test out of the real profile. -->
+                        <systemPropertyVariables>
+                            <user.home>${project.build.directory}/test-home</user.home>
+                        </systemPropertyVariables>
+                    </configuration>
                 </plugin>
             </plugins>
         </pluginManagement>

ts3-client/swing/src/main/java/com/ts3client/Main.java

@@ -15,9 +15,10 @@ import javax.swing.SwingUtilities;
 public final class Main {
 
     public static void main(String[] args) {
-        // ts3j is verbose by default; keep the console quiet unless debugging.
+        // ts3j is verbose by default; keep the console quiet unless asked for its protocol log
+        // (-Dts3j.debug=true, written to stderr).
         try {
-            com.github.manevolent.ts3j.util.Ts3Debugging.setEnabled(false);
+            com.github.manevolent.ts3j.util.Ts3Debugging.setEnabled(Boolean.getBoolean("ts3j.debug"));
         } catch (Throwable ignored) {
         }