For Qt GUI, create a temp directory per every boot of application that can be used to store temporary files for things such as netplay roms. This folder is deleted at application exit.

src/drivers/Qt/ConsoleWindow.cpp

@@ -47,6 +47,7 @@
 #include <QActionGroup>
 #include <QShortcut>
 #include <QUrl>
+#include <QDir>
 
 #include "../../fceu.h"
 #include "../../fds.h"
@@ -125,6 +126,12 @@ consoleWin_t::consoleWin_t(QWidget *parent)
 	//QString libpath = QLibraryInfo::location(QLibraryInfo::PluginsPath);
 	//printf("LibPath: '%s'\n", libpath.toLocal8Bit().constData() );
 
+	tempDir = new QTemporaryDir();
+	if (tempDir->isValid())
+	{
+		printf("Temp Folder: %s\n", tempDir->path().toLocal8Bit().constData());
+	}
+
 #ifdef __APPLE__
 	qt_set_sequence_auto_mnemonic(true);
 #endif
@@ -385,6 +392,11 @@ consoleWin_t::~consoleWin_t(void)
 		consoleWindow = NULL;
 	}
 
+	if (tempDir != nullptr)
+	{
+		delete tempDir;
+		tempDir = nullptr;
+	}
 }
 
 int consoleWin_t::videoInit(void)
@@ -4729,6 +4741,20 @@ void consoleWin_t::loadMostRecentROM(void)
 	FCEU_WRAPPER_UNLOCK();
 }
 
+QString consoleWin_t::getTempDir()
+{
+	QString path;
+	if (tempDir->isValid())
+	{
+		path = tempDir->path();
+	}
+	else
+	{
+		path = QDir::tempPath();
+	}
+	return path;
+}
+
 int consoleWin_t::getPeriodicInterval(void)
 {
 	return gameTimer->interval();

src/drivers/Qt/ConsoleWindow.h

@@ -23,6 +23,7 @@
 #include <QCursor>
 #include <QMutex>
 #include <QColor>
+#include <QTemporaryDir>
 #if QT_VERSION >= QT_VERSION_CHECK(6,0,0)
 #include <QRecursiveMutex>
 #endif
@@ -184,6 +185,8 @@ class  consoleWin_t : public QMainWindow
 
 		QColor *getVideoBgColorPtr(void){ return &videoBgColor; }
 
+		QString getTempDir();
+
 	protected:
 		consoleMenuBar *menubar;
 
@@ -271,6 +274,7 @@ class  consoleWin_t : public QMainWindow
 		QTimer  *gameTimer;
 		QColor   videoBgColor;
 		ColorMenuItem *bgColorMenuItem;
+		QTemporaryDir *tempDir;
 
 		std::string errorMsg;
 		bool        errorMsgValid;

src/drivers/Qt/NetPlay.cpp

@@ -379,9 +379,11 @@ int NetPlayServer::sendRomLoadReq( NetPlayClient *client )
 
 	rewind(fp);
 
+	QFileInfo fileInfo(GameInfo->filename);
+
 	msg.hdr.msgSize += fileSize;
 	msg.fileSize     = fileSize;
-	Strlcpy( msg.fileName, GameInfo->filename, sizeof(msg.fileName) );
+	Strlcpy( msg.fileName, fileInfo.fileName().toLocal8Bit().constData(), sizeof(msg.fileName) );
 
 	printf("Sending ROM Load Request: %s  %lu\n", filepath, fileSize );
 
@@ -1958,15 +1960,17 @@ void NetPlayClient::clientProcessMessage( void *msgBuf, size_t msgSize )
 		break;
 		case NETPLAY_LOAD_ROM_REQ:
 		{
-			QTemporaryFile tmpFile;
 			netPlayLoadRomReq *msg = static_cast<netPlayLoadRomReq*>(msgBuf);
 			msg->toHostByteOrder();
 			const char *romData = &static_cast<const char*>(msgBuf)[ sizeof(netPlayLoadRomReq) ];
 
-			FCEU_printf("Load ROM Request Received: %s\n", msg->fileName);
+			QFileInfo fileInfo = QFileInfo(msg->fileName);
+			QString tempPath = consoleWindow->getTempDir() + QString("/") + fileInfo.fileName();
+			FCEU_printf("Load ROM Request Received: %s\n", fileInfo.fileName().toLocal8Bit().constData());
 
-			tmpFile.setFileTemplate(QDir::tempPath() + QString("/tmpRom_XXXXXX.nes"));
-			tmpFile.open();
+			QFile tmpFile( tempPath );
+			//tmpFile.setFileTemplate(QDir::tempPath() + QString("/tmpRom_XXXXXX.nes"));
+			tmpFile.open(QIODeviceBase::ReadWrite);
 			QString filepath = tmpFile.fileName();
 			printf("Dumping Temp Rom to: %s\n", tmpFile.fileName().toLocal8Bit().constData());
 			tmpFile.write( romData, msgSize );