Allow returning of native error code if port does not open successfully

src/main/c/Posix/SerialPort_Posix.c

@@ -2,7 +2,7 @@
  * SerialPort_Posix.c
  *
  *       Created on:  Feb 25, 2012
- *  Last Updated on:  Jan 04, 2022
+ *  Last Updated on:  Jan 11, 2022
  *           Author:  Will Hedgecock
  *
  * Copyright (C) 2012-2022 Fazecast, Inc.
@@ -315,6 +315,8 @@ JNIEXPORT jlong JNICALL Java_com_fazecast_jSerialComm_SerialPort_openPortNative(
 	if (!port || (port->handle > 0))
 	{
 		(*env)->ReleaseStringUTFChars(env, portNameJString, portName);
+		port->errorLineNumber = __LINE__ - 3;
+		port->errorNumber = (!port ? 1 : 2);
 		return 0;
 	}
 
@@ -352,7 +354,7 @@ JNIEXPORT jlong JNICALL Java_com_fazecast_jSerialComm_SerialPort_openPortNative(
 
 	// Return a pointer to the serial port data structure
 	(*env)->ReleaseStringUTFChars(env, portNameJString, portName);
-	return (port->handle > 0) ? (jlong)(intptr_t)port : 0;
+	return (port->handle > 0) ? (jlong)(intptr_t)port : -(jlong)(intptr_t)port;
 }
 
 JNIEXPORT jboolean JNICALL Java_com_fazecast_jSerialComm_SerialPort_configPort(JNIEnv *env, jobject obj, jlong serialPortPointer)
@@ -671,7 +673,7 @@ JNIEXPORT jlong JNICALL Java_com_fazecast_jSerialComm_SerialPort_closePortNative
 	while (close(port->handle) && (errno == EINTR))
 		errno = 0;
 	port->handle = -1;
-	return -1;
+	return 0;
 }
 
 JNIEXPORT jint JNICALL Java_com_fazecast_jSerialComm_SerialPort_bytesAvailable(JNIEnv *env, jobject obj, jlong serialPortPointer)

src/main/c/Windows/SerialPort_Windows.c

@@ -2,7 +2,7 @@
  * SerialPort_Windows.c
  *
  *       Created on:  Feb 25, 2012
- *  Last Updated on:  Jan 06, 2022
+ *  Last Updated on:  Jan 11, 2022
  *           Author:  Will Hedgecock
  *
  * Copyright (C) 2012-2022 Fazecast, Inc.
@@ -381,6 +381,8 @@ JNIEXPORT jlong JNICALL Java_com_fazecast_jSerialComm_SerialPort_openPortNative(
 	if (!port || (port->handle != INVALID_HANDLE_VALUE))
 	{
 		(*env)->ReleaseStringChars(env, portNameJString, (const jchar*)portName);
+		port->errorLineNumber = __LINE__ - 3;
+		port->errorNumber = (!port ? 1 : 2);
 		return 0;
 	}
 
@@ -408,7 +410,7 @@ JNIEXPORT jlong JNICALL Java_com_fazecast_jSerialComm_SerialPort_openPortNative(
 
 	// Return a pointer to the serial port data structure
 	(*env)->ReleaseStringChars(env, portNameJString, (const jchar*)portName);
-	return (port->handle != INVALID_HANDLE_VALUE) ? (jlong)(intptr_t)port : 0;
+	return (port->handle != INVALID_HANDLE_VALUE) ? (jlong)(intptr_t)port : -(jlong)(intptr_t)port;
 }
 
 JNIEXPORT jboolean JNICALL Java_com_fazecast_jSerialComm_SerialPort_configPort(JNIEnv *env, jobject obj, jlong serialPortPointer)
@@ -671,15 +673,10 @@ JNIEXPORT jlong JNICALL Java_com_fazecast_jSerialComm_SerialPort_closePortNative
 
 	// Close the port
 	port->eventListenerRunning = 0;
-	if (!CloseHandle(port->handle))
-	{
-		port->handle = INVALID_HANDLE_VALUE;
-		port->errorLineNumber = __LINE__ - 3;
-		port->errorNumber = GetLastError();
-		return 0;
-	}
+	port->errorLineNumber = __LINE__ + 1;
+	port->errorNumber = (!CloseHandle(port->handle) ? GetLastError() : 0);
 	port->handle = INVALID_HANDLE_VALUE;
-	return -1;
+	return 0;
 }
 
 JNIEXPORT jint JNICALL Java_com_fazecast_jSerialComm_SerialPort_bytesAvailable(JNIEnv *env, jobject obj, jlong serialPortPointer)

src/main/java/com/fazecast/jSerialComm/SerialPort.java

@@ -2,7 +2,7 @@
  * SerialPort.java
  *
  *       Created on:  Feb 25, 2012
- *  Last Updated on:  Jan 06, 2022
+ *  Last Updated on:  Jan 11, 2022
  *           Author:  Will Hedgecock
  *
  * Copyright (C) 2012-2022 Fazecast, Inc.
@@ -524,7 +524,7 @@ public final class SerialPort
 	static final public int LISTENING_EVENT_PORT_DISCONNECTED = 0x10000000;
 
 	// Serial Port Parameters
-	private volatile long portHandle = -1;
+	private volatile long portHandle = 0;
 	private volatile int baudRate = 9600, dataBits = 8, stopBits = ONE_STOP_BIT, parity = NO_PARITY, eventFlags = 0;
 	private volatile int timeoutMode = TIMEOUT_NONBLOCKING, readTimeout = 0, writeTimeout = 0, flowControl = 0;
 	private volatile int sendDeviceQueueSize = 4096, receiveDeviceQueueSize = 4096;
@@ -687,7 +687,7 @@ public final class SerialPort
 	 * 
 	 * @return Source line of latest native code error.
 	 */
-	public final synchronized int getLastErrorLocation() { return (portHandle > 0) ? getLastErrorLocation(portHandle) : -1; }
+	public final synchronized int getLastErrorLocation() { return (portHandle != 0) ? getLastErrorLocation((portHandle > 0) ? portHandle : -portHandle) : -1; }
 	
 	/**
 	 * Returns the error number returned by the most recent native source code line that failed execution.
@@ -697,7 +697,7 @@ public final class SerialPort
 	 * 
 	 * @return Error number of the latest native code error.
 	 */
-	public final synchronized int getLastErrorCode() { return (portHandle > 0) ? getLastErrorCode(portHandle) : 0; }
+	public final synchronized int getLastErrorCode() { return (portHandle != 0) ? getLastErrorCode((portHandle > 0) ? portHandle : -portHandle) : 0; }
 
 	// Serial Port Setup Methods
 	private static native void initializeLibrary();						// Initializes the JNI code

src/test/java/com/fazecast/jSerialComm/SerialPortTest.java

@@ -119,6 +119,7 @@ public class SerialPortTest
 		System.out.println("\nOpening " + ubxPort.getSystemPortName() + ": " + ubxPort.getDescriptivePortName() + " - " + ubxPort.getPortDescription() + ": " + openedSuccessfully);
 		if (!openedSuccessfully)
 		{
+			System.out.println("Error code was " + ubxPort.getLastErrorCode() + " at Line " + ubxPort.getLastErrorLocation());
 			inputScanner.close();
 			return;
 		}