Fix Read Modified Query from Moshix bug report

lib3270j/src/main/java/haus/nightmare/lib3270j/Telnet3270Client.java

@@ -47,6 +47,7 @@ public class Telnet3270Client {
 
     private final java.util.concurrent.atomic.AtomicBoolean reconnecting = new java.util.concurrent.atomic.AtomicBoolean(false);
     private volatile Thread reconnectThread;
+    private volatile boolean intentionallyDisconnected = false;
 
     public Telnet3270Client(ConnectionConfig config) {
         this.config = config;
@@ -131,6 +132,7 @@ public class Telnet3270Client {
      * then returns while telnet/TN3270E negotiation continues asynchronously.
      */
     public void connect() throws IOException {
+        intentionallyDisconnected = false;
         log.info("Connecting to " + config.getHost() + ":" + config.getPort() +
             " model=" + config.getModel());
 
@@ -194,6 +196,7 @@ public class Telnet3270Client {
      * Disconnect from the host.
      */
     public void disconnect() {
+        intentionallyDisconnected = true;
         cancelAutoReconnect();
         if (connection != null) {
             try {
@@ -211,14 +214,20 @@ public class Telnet3270Client {
 
     public void cancelAutoReconnect() {
         reconnecting.set(false);
-        if (reconnectThread != null) {
+        Thread t = reconnectThread;
-            reconnectThread.interrupt();
+        if (t != null) {
+            t.interrupt();
+            try {
+                t.join(200);
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt();
+            }
             reconnectThread = null;
         }
     }
 
     public void initiateAutoReconnect() {
-        if (config == null || !config.isAutoReconnect()) {
+        if (intentionallyDisconnected || config == null || !config.isAutoReconnect()) {
             return;
         }
         if (!reconnecting.compareAndSet(false, true)) {

lib3270j/src/test/java/haus/nightmare/lib3270j/testutil/Mock3270Server.java

@@ -67,7 +67,9 @@ public class Mock3270Server implements AutoCloseable {
     }
 
     public Mock3270Server(int requestedPort) throws IOException {
-        this.serverSocket = new ServerSocket(requestedPort, 10, InetAddress.getByName("127.0.0.1"));
+        this.serverSocket = new ServerSocket();
+        this.serverSocket.setReuseAddress(true);
+        this.serverSocket.bind(new InetSocketAddress(InetAddress.getByName("127.0.0.1"), requestedPort), 10);
         this.port = serverSocket.getLocalPort();
         this.translator = new EbcdicTranslator();
         executor.submit(this::acceptLoop);
@@ -571,6 +573,11 @@ public class Mock3270Server implements AutoCloseable {
         } catch (Exception ignored) {}
         disconnectClient();
         executor.shutdownNow();
+        try {
+            executor.awaitTermination(200, TimeUnit.MILLISECONDS);
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt();
+        }
         log.info("Mock3270Server stopped");
     }
 }

lib3270j/src/test/java/haus/nightmare/lib3270j/testutil/Mock3270ServerIntegrationTest.java

@@ -76,8 +76,8 @@ public class Mock3270ServerIntegrationTest {
     public void testSendScreenAndVerifyPresentationSpace() throws Exception {
         ConnectionConfig config = new ConnectionConfig("127.0.0.1", server.getPort(), TerminalModel.IBM_3279_2);
         client = new Telnet3270Client(config);
-        assertTrue(client.connect(8000));
+        assertTrue(client.connect(8000), "Client should connect to mock server");
-        assertTrue(server.waitForHandshake(5, TimeUnit.SECONDS));
+        assertTrue(server.waitForHandshake(5, TimeUnit.SECONDS), "Server handshake should complete within 5s");
         waitForState(client, ConnectionState.CONNECTED_TN3270E, 5000);
 
         // Server sends formatted greeting screen at row 2, col 10
@@ -243,7 +243,10 @@ public class Mock3270ServerIntegrationTest {
         // Disconnect active client connection abruptly
         server.disconnectClient();
 
-        // Wait for client to detect disconnect and reconnect automatically
+        // Wait for client to detect disconnect and enter RECONNECTING
+        waitForState(client, ConnectionState.RECONNECTING, 5000);
+
+        // Wait for client to reconnect automatically
         waitForState(client, ConnectionState.CONNECTED_TN3270E, 8000);
         assertEquals(ConnectionState.CONNECTED_TN3270E, client.getConnectionState());
     }