fix #431, fix export cancels, and more debug prints

src/core.cpp

@@ -46,6 +46,8 @@ QList<ToxFile> Core::fileRecvQueue;
 Core::Core(Camera* cam, QThread *coreThread, QString loadPath) :
     tox(nullptr), camera(cam), loadPath(loadPath)
 {
+    qDebug() << "Core: loading Tox from" << loadPath;
+
     videobuf = new uint8_t[videobufsize];
     videoBusyness=0;
 
@@ -1184,6 +1186,13 @@ void Core::saveConfiguration(const QString& path)
 
 void Core::switchConfiguration(QString profile)
 {
+    if (profile.isEmpty())
+    {
+        qWarning() << "Core: got null profile to switch to, not switching";
+        return;
+    }
+    else
+        qDebug() << "Core: switching from" << Settings::getInstance().getCurrentProfile() << "to" << profile;
     saveConfiguration();
     
     toxTimer->stop();

src/widget/form/settings/identityform.cpp

@@ -132,7 +132,8 @@ void IdentityForm::onExportClicked()
     QString path = QFileDialog::getSaveFileName(this, tr("Export profile", "save dialog title"),
                     QDir::home().filePath(current), 
                     tr("Tox save file (*.tox)", "save dialog filter"));
-    QFile::copy(QDir(Settings::getSettingsDirPath()).filePath(current), path);
+    if (!path.isEmpty())
+        QFile::copy(QDir(Settings::getSettingsDirPath()).filePath(current), path);
 }
 
 void IdentityForm::onDeleteClicked()
@@ -157,6 +158,8 @@ void IdentityForm::onDeleteClicked()
 void IdentityForm::onImportClicked()
 {
     QString path = QFileDialog::getOpenFileName(this, tr("Import profile", "import dialog title"), QDir::homePath(), tr("Tox save file (*.tox)", "import dialog filter"));
+    if (path.isEmpty())
+        return;
     QFileInfo info(path);
     QString profile = info.completeBaseName();
     QString profilePath = QDir(Settings::getSettingsDirPath()).filePath(profile + Core::TOX_EXT);