Prevent deadlock when breakpoints are hit during main window exit

gui/qt/debugger.cpp

@@ -367,6 +367,7 @@ void MainWindow::debugExecute(uint32_t offset, uint8_t cmd) {
 
 void MainWindow::debugCommand(int reason, uint32_t data) {
     if (!guiEmuValid) {
+        emu.resume();
         return;
     }
 

gui/qt/emuthread.cpp

@@ -11,6 +11,8 @@
 #include "capture/animated-png.h"
 
 #include <QtCore/QVector>
+#include <QtCore/QEventLoop>
+#include <QtCore/QTimer>
 
 #include <cassert>
 #include <cstdarg>
@@ -396,11 +398,15 @@ void EmuThread::load(emu_data_t fileType, const QString &filePath) {
 }
 
 void EmuThread::stop() {
+    // Need to run events to allow queued slots to be processed during exit
+    QEventLoop eventLoop;
+    connect(this, &QThread::finished, &eventLoop, [&]() { eventLoop.exit(0); });
     if (!isRunning()) {
         return;
     }
     emu_exit();
-    if (!wait(500)) {
+    QTimer::singleShot(500, &eventLoop, [&]() { eventLoop.exit(1); });
+    if (eventLoop.exec()) {
         terminate();
         wait(500);
     }

gui/qt/mainwindow.cpp

@@ -1389,6 +1389,8 @@ void MainWindow::emuSaved(bool success) {
 }
 
 void MainWindow::closeEvent(QCloseEvent *e) {
+    guiEmuValid = false;
+
     if (!m_shutdown) {
         m_shutdown = true;
 
@@ -1422,7 +1424,6 @@ void MainWindow::closeEvent(QCloseEvent *e) {
         }
     }
 
-    guiEmuValid = false;
     emu.stop();
     QMainWindow::closeEvent(e);
 }