Add bugfixes from testing

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

@@ -435,6 +435,14 @@ public class ConnectionConfig {
             }
         }
 
+        // Parse [lu@]host[:port] (e.g. "00C2@mvs.host.com:1023")
+        String parsedLu = null;
+        int atIdx = s.indexOf('@');
+        if (atIdx > 0 && atIdx < s.length() - 1) {
+            parsedLu = s.substring(0, atIdx).trim();
+            s = s.substring(atIdx + 1).trim();
+        }
+
         String host = s;
         int port = (defaultPort > 0) ? defaultPort : (tls ? 992 : 23);
 
@@ -458,6 +466,9 @@ public class ConnectionConfig {
         }
 
         ConnectionConfig config = new ConnectionConfig(host, port, defaultModel != null ? defaultModel : TerminalModel.IBM_3279_4);
+        if (parsedLu != null && !parsedLu.isEmpty()) {
+            config.setLuName(parsedLu);
+        }
         config.setUseTls(tls);
         config.setTn3270eEnabled(tn3270e);
         config.setKeepAliveEnabled(keepAlive);

lib3270j/src/main/java/haus/nightmare/lib3270j/telnet/TelnetFSM.java

@@ -70,8 +70,22 @@ public class TelnetFSM {
 
     private List<String> getCandidateTerminalTypes() {
         List<String> list = new ArrayList<>();
+        String currentLu = null;
+        List<String> lus = config.getLuNames();
+        if (lus != null && !lus.isEmpty() && luIndex < lus.size()) {
+            currentLu = lus.get(luIndex);
+        } else if (config.getLuName() != null && !config.getLuName().trim().isEmpty()) {
+            currentLu = config.getLuName().trim();
+        }
+
         if (config.getTerminalName() != null && !config.getTerminalName().trim().isEmpty()) {
-            list.add(config.getTerminalName().trim());
+            String tName = config.getTerminalName().trim();
+            if (currentLu != null && !currentLu.isEmpty() && !tName.contains("@")) {
+                list.add(tName + "@" + currentLu);
+                list.add(tName);
+            } else {
+                list.add(tName);
+            }
             return list;
         }
         if (config.isDynamicModel()) {
@@ -82,8 +96,7 @@ public class TelnetFSM {
             list.add("IBM-3279-2");
             list.add("IBM-3278-2");
             list.add("UNKNOWN");
-            return list;
+        } else {
-        }
             TerminalModel model = config.getModel();
             list.add(model.getTerminalType());
             list.add(model.getBaseTerminalType());
@@ -100,6 +113,24 @@ public class TelnetFSM {
                 list.add("IBM-3278-2");
             }
             list.add("UNKNOWN");
+        }
+
+        if (currentLu != null && !currentLu.isEmpty()) {
+            List<String> luCandidates = new ArrayList<>();
+            for (String item : list) {
+                if (!"UNKNOWN".equalsIgnoreCase(item) && !item.contains("@")) {
+                    luCandidates.add(item + "@" + currentLu);
+                }
+            }
+            for (String item : list) {
+                if (!"UNKNOWN".equalsIgnoreCase(item)) {
+                    luCandidates.add(item);
+                }
+            }
+            luCandidates.add("UNKNOWN");
+            return luCandidates;
+        }
+
         return list;
     }
 
@@ -589,6 +620,9 @@ public class TelnetFSM {
             out.write(IAC);
             out.write(SE);
             sendBytes(out.toByteArray());
+            if (termType.contains("@")) {
+                connectedLu = termType.substring(termType.indexOf('@') + 1).trim();
+            }
             log.warning(">>> SENT SB TTYPE IS " + termType + " SE");
         }
     }

lib3270j/src/test/java/haus/nightmare/lib3270j/telnet/TelnetFSMTest.java

@@ -84,6 +84,41 @@ public class TelnetFSMTest {
         ConnectionConfig c4 = ConnectionConfig.parseHostString("non-e:vm.ibm.com", 23, TerminalModel.IBM_3279_4);
         assertFalse(c4.isTn3270eEnabled());
         assertEquals("vm.ibm.com", c4.getHost());
+
+        ConnectionConfig c5 = ConnectionConfig.parseHostString("00C2@mvs.hugfreevikings.wtf:1023", 23, TerminalModel.IBM_3279_4);
+        assertEquals("mvs.hugfreevikings.wtf", c5.getHost());
+        assertEquals(1023, c5.getPort());
+        assertEquals("00C2", c5.getLuName());
+
+        ConnectionConfig c6 = ConnectionConfig.parseHostString("L:TSO01@secure.mvs.com:992", 23, TerminalModel.IBM_3279_4);
+        assertTrue(c6.isUseTls());
+        assertEquals("secure.mvs.com", c6.getHost());
+        assertEquals(992, c6.getPort());
+        assertEquals("TSO01", c6.getLuName());
+    }
+
+    @Test
+    public void testPlainTn3270TTypeWithLuName() {
+        config.setTn3270eEnabled(false);
+        config.setLuName("00C2");
+        fsm.onConnected();
+
+        feedBytes(TelnetConstants.IAC, TelnetConstants.DO, TelnetConstants.TELOPT_TTYPE);
+        // Host sends SB TTYPE SEND
+        feedBytes(TelnetConstants.IAC, TelnetConstants.SB, TelnetConstants.TELOPT_TTYPE,
+                  TelnetConstants.TELQUAL_SEND,
+                  TelnetConstants.IAC, TelnetConstants.SE);
+
+        boolean foundTtypeLu = false;
+        for (byte[] pkt : connection.sentData) {
+            String s = new String(pkt, java.nio.charset.StandardCharsets.ISO_8859_1);
+            if (s.contains("IBM-3279-4-E@00C2")) {
+                foundTtypeLu = true;
+                break;
+            }
+        }
+        assertTrue(foundTtypeLu, "Plain TN3270 TTYPE IS must append @<luName> when configured");
+        assertEquals("00C2", fsm.getConnectedLu());
     }
 
     @Test