Shutdown gdb when 'close' event happens.

This should take care of detaching from a remote pid.

src/SeerGdbWidget.cpp

@@ -749,6 +749,20 @@ void SeerGdbWidget::handleGdbCoreFileExecutable () {
     handleGdbCommand(QString("-target-select core %1").arg(executableCoreFilename()));
 }
 
+void SeerGdbWidget::handleGdbShutdown () {
+
+    if (isGdbRuning() == false) {
+        return;
+    }
+
+    // Give the gdb and 'exit' command.
+    // This should handle detaching from an attached pid.
+    handleGdbExit();
+
+    // Kill the gdb.
+    killGdb();
+}
+
 void SeerGdbWidget::handleGdbRunToLine (QString fullname, int lineno) {
 
     if (executableLaunchMode() == "") {

src/SeerGdbWidget.h

@@ -111,6 +111,7 @@ class SeerGdbWidget : public QWidget, protected Ui::SeerGdbWidgetForm {
         void                                handleGdbAttachExecutable           ();
         void                                handleGdbConnectExecutable          ();
         void                                handleGdbCoreFileExecutable         ();
+        void                                handleGdbShutdown                   ();
         void                                handleGdbRunToLine                  (QString fullname, int lineno);
         void                                handleGdbNext                       ();
         void                                handleGdbStep                       ();

src/SeerMainWindow.cpp

@@ -106,6 +106,8 @@ SeerMainWindow::SeerMainWindow(QWidget* parent) : QMainWindow(parent) {
 
     QObject::connect(runStatus,                         &SeerRunStatusIndicator::statusChanged, this,           &SeerMainWindow::handleRunStatusChanged);
 
+    QObject::connect(qApp,                              &QApplication::aboutToQuit,             gdbWidget,      &SeerGdbWidget::handleGdbShutdown);
+
     // Restore window settings.
     readSettings();