Fix YMS bug

.gitignore

@@ -1,3 +1,4 @@
+*.log
 .DS_Store
 *.jar
 build

README.md

@@ -73,29 +73,6 @@ The resulting standalone JAR is created at `build/j3270.jar`.
 
 ---
 
-## 🏷️ How to Tag & Publish Releases
-
-Releases can be published automatically to Gitea via Git tags:
-
-```bash
-# 1. Create a version tag
-git tag -a v0.1.0 -m "Release v0.1.0"
-
-# 2. Push the tag to Gitea
-git push origin v0.1.0
-```
-
-Pushing any `v*` tag triggers the automated release workflow (`.gitea/workflows/release.yaml`), which runs tests, builds the JAR, and publishes a new Gitea Release with `j3270.jar` attached automatically.
-
----
-
-## 🔍 Topics & Discoverability
-
-Suggested keywords/topics for repository indexing:
-`tn3270` · `tn3270e` · `ibm-3270` · `mainframe` · `terminal-emulator` · `x3270` · `ind-file` · `file-transfer` · `ebcdic` · `z-vm` · `z-os` · `cms` · `tso` · `cics` · `java` · `desktop-app`
-
----
-
 ## 🤝 Contributing
 
 Contributions and issue reports are welcome! Please feel free to open a bug report or feature request via the Gitea issue tracker.

j3270/src/main/java/org/pubvm/j3270/J3270App.java

@@ -438,16 +438,37 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
             }
         }
 
-        // Configure logging over the absolute root logger
+        // Configure logging for application packages
         Logger globalRoot = Logger.getLogger("");
         for (java.util.logging.Handler h : globalRoot.getHandlers()) {
             globalRoot.removeHandler(h);
         }
-        globalRoot.setLevel(debug ? Level.ALL : Level.WARNING);
+        globalRoot.setLevel(Level.WARNING);
+
         ConsoleHandler handler = new ConsoleHandler();
-        handler.setLevel(Level.ALL);
+        handler.setLevel(debug ? Level.ALL : Level.INFO);
         handler.setFormatter(new SimpleFormatter());
-        globalRoot.addHandler(handler);
+
+        Logger appLogger = Logger.getLogger("org.pubvm.j3270");
+        appLogger.setLevel(Level.ALL);
+        appLogger.addHandler(handler);
+        appLogger.setUseParentHandlers(false);
+
+        Logger libLogger = Logger.getLogger("org.lib3270j");
+        libLogger.setLevel(Level.ALL);
+        libLogger.addHandler(handler);
+        libLogger.setUseParentHandlers(false);
+
+        try {
+            java.util.logging.FileHandler fileHandler = new java.util.logging.FileHandler("j3270.log", 10 * 1024 * 1024, 1, false);
+            fileHandler.setLevel(Level.ALL);
+            fileHandler.setFormatter(new SimpleFormatter());
+            appLogger.addHandler(fileHandler);
+            libLogger.addHandler(fileHandler);
+            log.info("Logging protocol trace to j3270.log");
+        } catch (Exception e) {
+            System.err.println("Could not create j3270.log: " + e.getMessage());
+        }
 
         // Load INI config file if specified
         if (configFile != null) {

j3270/src/main/java/org/pubvm/j3270/ui/TerminalPanel.java

@@ -889,10 +889,20 @@ public class TerminalPanel extends JPanel {
                 if (faIsHigh(currentFA & 0xFF))
                     bold = true;
 
-                // Handle invisible fields (zero intensity)
+                // Handle invisible fields (zero intensity / password fields)
+                // Modern UX: render '*' for typed characters so user sees length/digit count
                 if (faIsZero(currentFA & 0xFF)) {
                     g2.setColor(this.bgColor);
                     g2.fillRect(x, y, cellWidth, cellHeight);
+
+                    char ch = ea.ucs4;
+                    if (ch > 0x20 && ch != 0xFF) {
+                        Font f = bold ? terminalFont.deriveFont(Font.BOLD) : terminalFont;
+                        g2.setFont(f);
+                        g2.setColor(fgColor);
+                        g2.drawString("*", x, y + fontAscent);
+                    }
+
                     if (isCellSelected(row, col)) {
                         g2.setColor(SELECTION_COLOR);
                         g2.fillRect(x, y, cellWidth, cellHeight);

lib3270j/src/main/java/org/lib3270j/datastream/DataStreamProcessor.java

@@ -6,6 +6,7 @@ import org.lib3270j.charset.EbcdicTranslator;
 import org.lib3270j.listener.ScreenUpdateListener;
 import static org.lib3270j.protocol.DS3270Constants.*;
 
+import java.io.ByteArrayOutputStream;
 import java.util.List;
 import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.logging.Logger;
@@ -451,8 +452,8 @@ public class DataStreamProcessor {
                         pos += 4;
                     }
 
-                    // Fill from current position to target
-                    while (baddr != toAddr) {
+                    // Fill from current position to target (do-while wraps entire buffer if baddr == toAddr)
+                    do {
                         ExtendedAttribute ea = screen.getCell(baddr);
                         ea.fa = 0; // Destroy previous field attribute if any
                         ea.ec = (byte) fillChar;
@@ -461,7 +462,7 @@ public class DataStreamProcessor {
                         ea.gr = (byte) currentGr;
                         ea.cs = fillCs;
                         baddr = (baddr + 1) % size;
-                    }
+                    } while (baddr != toAddr);
                     screen.setBufferAddress(baddr);
                     lastWasOrder = true;
                     break;
@@ -476,7 +477,7 @@ public class DataStreamProcessor {
                     if (toAddr >= size)
                         toAddr = toAddr % size;
 
-                    while (baddr != toAddr) {
+                    do {
                         ExtendedAttribute ea = screen.getCell(baddr);
                         if (!ea.isFieldAttribute()) {
                             int faAddr = screen.findFieldAttribute(baddr);
@@ -491,7 +492,7 @@ public class DataStreamProcessor {
                             }
                         }
                         baddr = (baddr + 1) % size;
-                    }
+                    } while (baddr != toAddr);
                     screen.setBufferAddress(baddr);
                     pos += 3;
                     lastWasOrder = true;
@@ -637,7 +638,13 @@ public class DataStreamProcessor {
 
         outputPos = 0;
 
-        int aid = AID_NO; // Last AID
+        int aid = (inputProcessor != null && inputProcessor.getLastAid() != 0)
+                ? inputProcessor.getLastAid()
+                : AID_NO;
+        if (inputProcessor != null) {
+            inputProcessor.setLastAid(AID_NO);
+        }
+
         int size = screen.getRows() * screen.getCols();
 
         // AID byte
@@ -649,31 +656,56 @@ public class DataStreamProcessor {
         outputWrite(caddr[1] & 0xFF);
 
         if (!screen.isFormatted()) {
-            // Unformatted: send everything
-            if (all) {
-                for (int i = 0; i < size; i++) {
-                    outputWrite(screen.getCell(i).ec & 0xFF);
+            // Unformatted screen: send data up to last non-null
+            int lastNonNull = -1;
+            for (int i = size - 1; i >= 0; i--) {
+                if (screen.getCell(i).ec != 0) {
+                    lastNonNull = i;
+                    break;
+                }
+            }
+            if (lastNonNull >= 0) {
+                for (int i = 0; i <= lastNonNull; i++) {
+                    int b = screen.getCell(i).ec & 0xFF;
+                    outputWrite(b != 0 ? b : 0x40);
                 }
             }
         } else {
-            // Formatted: send modified fields
+            // Formatted screen: send modified fields with trailing NULLs stripped
             for (int i = 0; i < size; i++) {
                 ExtendedAttribute ea = screen.getCell(i);
                 if (ea.isFieldAttribute() && (all || faIsModified(ea.fa & 0xFF))) {
                     int fieldStart = (i + 1) % size;
-                    // Send SBA for field start
+
+                    // Collect field data and find last non-null byte
+                    ByteArrayOutputStream fieldData = new ByteArrayOutputStream();
+                    int pos = fieldStart;
+                    int lastNonNull = -1;
+                    int fieldLen = 0;
+                    while (!screen.getCell(pos).isFieldAttribute()) {
+                        int b = screen.getCell(pos).ec & 0xFF;
+                        fieldData.write(b);
+                        if (b != 0x00) {
+                            lastNonNull = fieldLen;
+                        }
+                        fieldLen++;
+                        pos = (pos + 1) % size;
+                        if (pos == fieldStart)
+                            break;
+                    }
+
+                    // Always send SBA and address
                     outputWrite(ORDER_SBA);
                     byte[] addr = encodeAddress(fieldStart, screen.getRows(), screen.getCols());
                     outputWrite(addr[0] & 0xFF);
                     outputWrite(addr[1] & 0xFF);
 
-                    // Send field contents until next FA
-                    int pos = fieldStart;
-                    while (pos < size && !screen.getCell(pos).isFieldAttribute()) {
-                        outputWrite(screen.getCell(pos).ec & 0xFF);
-                        pos = (pos + 1) % size;
-                        if (pos == fieldStart)
-                            break;
+                    // Send field data (strip trailing nulls)
+                    if (lastNonNull >= 0) {
+                        byte[] allData = fieldData.toByteArray();
+                        for (int k = 0; k <= lastNonNull; k++) {
+                            outputWrite(allData[k] & 0xFF);
+                        }
                     }
                 }
             }

lib3270j/src/main/java/org/lib3270j/datastream/QueryReplyBuilder.java

@@ -265,20 +265,21 @@ public class QueryReplyBuilder {
 
     private byte[] buildImplicitPartition(int maxCols, int maxRows) {
         ByteArrayOutputStream out = new ByteArrayOutputStream(22);
-        // Implicit partition sizes, 2 self-defining parameters
+        // Implicit partition sizes SDP (Self-Defining Parameter)
 
-        // SDP 1: Default screen size
         out.write(0x00); // flags
         out.write(0x00); // reserved
-        out.write(0x0b); // SDP length
+        // SDP 1: Implicit partition sizes
+        out.write(0x00); // SDP length high byte
+        out.write(0x0b); // SDP length low byte (11 bytes: 2 len + 1 type + 1 res + 8 dims)
         out.write(0x01); // SDP type: implicit partition sizes
         out.write(0x00); // reserved
-        // Default
+        // Default dimensions (Model 2: 80x24)
         out.write((MODEL_2_COLS >> 8) & 0xFF);
         out.write(MODEL_2_COLS & 0xFF);
         out.write((MODEL_2_ROWS >> 8) & 0xFF);
         out.write(MODEL_2_ROWS & 0xFF);
-        // Alternate
+        // Alternate dimensions
         out.write((maxCols >> 8) & 0xFF);
         out.write(maxCols & 0xFF);
         out.write((maxRows >> 8) & 0xFF);

lib3270j/src/main/java/org/lib3270j/input/InputProcessor.java

@@ -138,9 +138,10 @@ public class InputProcessor {
         }
 
         // Advance cursor
+        int startAdvance = baddr;
         baddr = (baddr + 1) % size;
-        // Skip over field attributes
-        while (screen.getCell(baddr).isFieldAttribute()) {
+        // Skip over field attributes safely
+        while (screen.getCell(baddr).isFieldAttribute() && baddr != startAdvance) {
             baddr = (baddr + 1) % size;
         }
         screen.setCursorAddress(baddr);
@@ -255,18 +256,26 @@ public class InputProcessor {
                 }
             }
         } else {
-            // Unformatted screen in 3270 mode:
-            // Send character data from address 0 up to last non-null character
-            int size = screen.getRows() * screen.getCols();
-            int lastNonNull = -1;
-            for (int i = size - 1; i >= 0; i--) {
-                if (screen.getCell(i).ec != 0) {
-                    lastNonNull = i;
+            // Unformatted screen in 3270 mode (e.g. line-mode console):
+            // Send AID + cursor address + only the active input line (row containing cursor)
+            int cols = screen.getCols();
+            int curAddr = screen.getCursorAddress();
+            int row = curAddr / cols;
+            int rowStart = row * cols;
+            int rowEnd = rowStart + cols;
+
+            // Find last non-null, non-blank character on the current line
+            int lastChar = rowStart - 1;
+            for (int i = rowEnd - 1; i >= rowStart; i--) {
+                int ec = screen.getCell(i).ec & 0xFF;
+                if (ec != 0x00 && ec != 0x40) {
+                    lastChar = i;
                     break;
                 }
             }
-            if (lastNonNull >= 0) {
-                for (int i = 0; i <= lastNonNull; i++) {
+
+            if (lastChar >= rowStart) {
+                for (int i = rowStart; i <= lastChar; i++) {
                     int b = screen.getCell(i).ec & 0xFF;
                     out.write(b != 0 ? b : 0x40);
                 }
@@ -325,6 +334,13 @@ public class InputProcessor {
         screen.setCursorAddress(addr);
     }
 
+    public int getLastAid() { return lastAid; }
+    public void setLastAid(int aid) { this.lastAid = aid; }
+
+    public void setCursorAddress(int baddr) {
+        screen.setCursorAddress(baddr);
+    }
+
     public void backTab() {
         // Find previous unprotected field
         int addr = screen.getCursorAddress();

lib3270j/src/main/java/org/lib3270j/telnet/TelnetConnection.java

@@ -132,10 +132,14 @@ public class TelnetConnection {
                     if (log.isLoggable(Level.FINE)) {
                         log.fine("RCVD " + n + " bytes: " + formatHex(buf, 0, n));
                     }
-                    for (int i = 0; i < n; i++) {
-                        fsm.feedByte(buf[i] & 0xFF);
+                    try {
+                        for (int i = 0; i < n; i++) {
+                            fsm.feedByte(buf[i] & 0xFF);
+                        }
+                        fsm.endOfNetworkData();
+                    } catch (Throwable t) {
+                        log.log(Level.SEVERE, "Exception processing incoming data stream", t);
                     }
-                    fsm.endOfNetworkData();
                 }
             }
         } catch (SocketException e) {
@@ -148,6 +152,11 @@ public class TelnetConnection {
                 log.log(Level.WARNING, "Read error", e);
                 fsm.onError("Read error: " + e.getMessage());
             }
+        } catch (Throwable t) {
+            if (running) {
+                log.log(Level.SEVERE, "Unexpected fatal error in readLoop", t);
+                fsm.onError("Network loop error: " + t.getMessage());
+            }
         }
     }