fix(video): don't use pointers to temporary objects

fixes #4764

src/net/autoupdate.cpp

@@ -595,13 +595,14 @@ void AutoUpdater::installLocalUpdate()
 // Workaround QTBUG-7645
 // QProcess fails silently when elevation is required instead of showing a UAC prompt on Win7/Vista
 #ifdef Q_OS_WIN
-    QString modulePath = qApp->applicationDirPath().replace('/', '\\');
-    HINSTANCE result = ::ShellExecuteW(0, L"open", updaterBin.toStdWString().c_str(), 0,
-                                       modulePath.toStdWString().c_str(), SW_SHOWNORMAL);
+    const std::wstring modulePath = qApp->applicationDirPath().replace('/', '\\').toStdWString();
+    const std::wstring updaterBinPath = updaterBin.toStdWString();
+    HINSTANCE result = ::ShellExecuteW(0, L"open", updaterBinPath.c_str(), 0,
+                                       modulePath.c_str(), SW_SHOWNORMAL);
     if (result == (HINSTANCE)SE_ERR_ACCESSDENIED) {
         // Requesting elevation
-        result = ::ShellExecuteW(0, L"runas", updaterBin.toStdWString().c_str(), 0,
-                                 modulePath.toStdWString().c_str(), SW_SHOWNORMAL);
+        result = ::ShellExecuteW(0, L"runas", updaterBinPath.c_str(), 0,
+                                 modulePath.c_str(), SW_SHOWNORMAL);
     }
     if (result <= (HINSTANCE)32)
         failExit();

src/platform/camera/v4l2.cpp

@@ -62,7 +62,8 @@ static int deviceOpen(QString devName, int* error)
     struct v4l2_capability cap;
     int fd;
 
-    fd = open(devName.toStdString().c_str(), O_RDWR, 0);
+    const std::string devNameString = devName.toStdString();
+    fd = open(devNameString.c_str(), O_RDWR, 0);
     if (fd < 0) {
         *error = errno;
         return fd;
@@ -183,9 +184,11 @@ QVector<QPair<QString, QString>> v4l2::getDeviceList()
     closedir(dir);
 
     for (QString file : deviceFiles) {
-        int fd = open(file.toStdString().c_str(), O_RDWR);
-        if (fd < 0)
+        const std::string filePath = file.toStdString();
+        int fd = open(filePath.c_str(), O_RDWR);
+        if (fd < 0) {
             continue;
+        }
 
         v4l2_capability caps;
         ioctl(fd, VIDIOC_QUERYCAP, &caps);

src/video/cameradevice.cpp

@@ -84,8 +84,10 @@ CameraDevice* CameraDevice::open(QString devName, AVDictionary** options)
     AVFormatContext* fctx = nullptr;
     CameraDevice* dev = openDevices.value(devName);
     int aduration;
-    if (dev)
+    std::string devString;
+    if (dev) {
         goto out;
+    }
 
     AVInputFormat* format;
     if (devName.startsWith("x11grab#")) {
@@ -98,8 +100,10 @@ CameraDevice* CameraDevice::open(QString devName, AVDictionary** options)
         format = iformat;
     }
 
-    if (avformat_open_input(&fctx, devName.toStdString().c_str(), format, options) < 0)
+    devString = devName.toStdString();
+    if (avformat_open_input(&fctx, devString.c_str(), format, options) < 0) {
         goto out;
+    }
 
 // Fix avformat_find_stream_info hanging on garbage input
 #if FF_API_PROBESIZE_32
@@ -149,6 +153,14 @@ CameraDevice* CameraDevice::open(QString devName, VideoMode mode)
         return nullptr;
     }
 
+    int FPS = 5;
+    if (mode.FPS) {
+        FPS = mode.FPS;
+    }
+
+    const std::string videoSize = QStringLiteral("%1x%2").arg(mode.width).arg(mode.height).toStdString();
+    const std::string framerate = QString{}.setNum(FPS).toStdString();
+
     AVDictionary* options = nullptr;
     if (!iformat)
         ;
@@ -168,20 +180,14 @@ CameraDevice* CameraDevice::open(QString devName, VideoMode mode)
             screen.setWidth((screen.width() * pixRatio) - 2);
             screen.setHeight((screen.height() * pixRatio) - 2);
         }
-        av_dict_set(&options, "video_size",
-                    QString("%1x%2").arg(screen.width()).arg(screen.height()).toStdString().c_str(),
-                    0);
+        const std::string screenVideoSize = QStringLiteral("%1x%2").arg(screen.width()).arg(screen.height()).toStdString();
+        av_dict_set(&options, "video_size", screenVideoSize.c_str(), 0);
         devName += QString("+%1,%2").arg(QString().setNum(mode.x), QString().setNum(mode.y));
 
-        int FPS = 5;
-        if (mode.FPS)
-            FPS = mode.FPS;
-
-        av_dict_set(&options, "framerate", QString().setNum(FPS).toStdString().c_str(), 0);
+        av_dict_set(&options, "framerate", framerate.c_str(), 0);
     } else if (iformat->name == QString("video4linux2,v4l2") && mode) {
-        av_dict_set(&options, "video_size",
-                    QString("%1x%2").arg(mode.width).arg(mode.height).toStdString().c_str(), 0);
-        av_dict_set(&options, "framerate", QString().setNum(mode.FPS).toStdString().c_str(), 0);
+        av_dict_set(&options, "video_size", videoSize.c_str(), 0);
+        av_dict_set(&options, "framerate", framerate.c_str(), 0);
         const std::string pixelFormatStr = v4l2::getPixelFormatString(mode.pixel_format).toStdString();
         const char* pixel_format = pixelFormatStr.c_str();
         if (strncmp(pixel_format, "unknown", 7) != 0) {
@@ -191,25 +197,25 @@ CameraDevice* CameraDevice::open(QString devName, VideoMode mode)
 #endif
 #ifdef Q_OS_WIN
     else if (devName.startsWith("gdigrab#")) {
-        av_dict_set(&options, "framerate", QString().setNum(5).toStdString().c_str(), 0);
-        av_dict_set(&options, "offset_x", QString().setNum(mode.x).toStdString().c_str(), 0);
-        av_dict_set(&options, "offset_y", QString().setNum(mode.y).toStdString().c_str(), 0);
-        av_dict_set(&options, "video_size",
-                    QString("%1x%2").arg(mode.width).arg(mode.height).toStdString().c_str(), 0);
+
+        const std::string offsetX = QString().setNum(mode.x).toStdString();
+        const std::string offsetY = QString().setNum(mode.y).toStdString();
+        av_dict_set(&options, "framerate", framerate.c_str(), 0);
+        av_dict_set(&options, "offset_x", offsetX.c_str(), 0);
+        av_dict_set(&options, "offset_y", offsetY.c_str(), 0);
+        av_dict_set(&options, "video_size", videoSize.c_str(), 0);
     } else if (iformat->name == QString("dshow") && mode) {
-        av_dict_set(&options, "video_size",
-                    QString("%1x%2").arg(mode.width).arg(mode.height).toStdString().c_str(), 0);
-        av_dict_set(&options, "framerate", QString().setNum(mode.FPS).toStdString().c_str(), 0);
+        av_dict_set(&options, "video_size", videoSize.c_str(), 0);
+        av_dict_set(&options, "framerate", framerate.c_str(), 0);
     }
 #endif
 #ifdef Q_OS_OSX
     else if (iformat->name == QString("avfoundation")) {
         if (mode) {
-            av_dict_set(&options, "video_size",
-                        QString("%1x%2").arg(mode.width).arg(mode.height).toStdString().c_str(), 0);
-            av_dict_set(&options, "framerate", QString().setNum(mode.FPS).toStdString().c_str(), 0);
+            av_dict_set(&options, "video_size", videoSize.c_str(), 0);
+            av_dict_set(&options, "framerate", framerate.c_str(), 0);
         } else if (devName.startsWith(avfoundation::CAPTURE_SCREEN)) {
-            av_dict_set(&options, "framerate", QString().setNum(5).toStdString().c_str(), 0);
+            av_dict_set(&options, "framerate", framerate.c_str(), 0);
             av_dict_set_int(&options, "capture_cursor", 1, 0);
             av_dict_set_int(&options, "capture_mouse_clicks", 1, 0);
         }
@@ -221,8 +227,9 @@ CameraDevice* CameraDevice::open(QString devName, VideoMode mode)
     }
 
     CameraDevice* dev = open(devName, &options);
-    if (options)
+    if (options) {
         av_dict_free(&options);
+    }
 
     return dev;
 }

src/widget/form/settings/avform.cpp

@@ -280,14 +280,15 @@ void AVForm::fillCameraModesComboBox()
         VideoMode mode = videoModes[i];
 
         QString str;
-        QString pixelFormat = CameraDevice::getPixelFormatString(mode.pixel_format);
+        std::string pixelFormat = CameraDevice::getPixelFormatString(mode.pixel_format).toStdString();
         qDebug("width: %d, height: %d, FPS: %f, pixel format: %s\n", mode.width, mode.height,
-               mode.FPS, pixelFormat.toStdString().c_str());
+               mode.FPS, pixelFormat.c_str());
 
-        if (mode.height && mode.width)
+        if (mode.height && mode.width) {
             str += QString("%1p").arg(mode.height);
-        else
+        } else {
             str += tr("Default resolution");
+        }
 
         videoModescomboBox->addItem(str);
     }
@@ -320,9 +321,9 @@ void AVForm::fillScreenModesComboBox()
 
     for (int i = 0; i < videoModes.size(); ++i) {
         VideoMode mode = videoModes[i];
-        QString pixelFormat = CameraDevice::getPixelFormatString(mode.pixel_format);
+        std::string pixelFormat = CameraDevice::getPixelFormatString(mode.pixel_format).toStdString();
         qDebug("%dx%d+%d,%d FPS: %f, pixel format: %s\n", mode.width, mode.height, mode.x, mode.y,
-               mode.FPS, pixelFormat.toStdString().c_str());
+               mode.FPS, pixelFormat.c_str());
 
         QString name;
         if (mode.width && mode.height)

src/widget/qrwidget.cpp

@@ -85,7 +85,8 @@ void QRWidget::paintImage()
     // https://fukuchi.org/works/qrencode/manual/qrencode_8h.html#a4cebc3c670efe1b8866b14c42737fc8f
     // any mode other than QR_MODE_8 or QR_MODE_KANJI results in EINVAL. First 1 is version, second
     // is case sensitivity
-    QRcode* qr = QRcode_encodeString(data.toStdString().c_str(), 1, QR_ECLEVEL_M, QR_MODE_8, 1);
+    const std::string dataString = data.toStdString();
+    QRcode* qr = QRcode_encodeString(dataString.c_str(), 1, QR_ECLEVEL_M, QR_MODE_8, 1);
 
     if (qr != nullptr) {
         QColor fg("black");

src/widget/systemtrayicon.cpp

@@ -49,9 +49,10 @@ SystemTrayIcon::SystemTrayIcon()
         }
         backendType = SystrayBackendType::Unity;
         unityMenu = gtk_menu_new();
+        const std::string settingsDirString = settingsDir.toStdString();
         unityIndicator =
             app_indicator_new_with_path("qTox", "icon", APP_INDICATOR_CATEGORY_APPLICATION_STATUS,
-                                        settingsDir.toStdString().c_str());
+                                        settingsDirString.c_str());
         app_indicator_set_menu(unityIndicator, GTK_MENU(unityMenu));
     }
 #endif
@@ -141,15 +142,15 @@ void SystemTrayIcon::setContextMenu(QMenu* menu)
         g_signal_connect(statusNotifier, "secondary_activate", G_CALLBACK(callbackMiddleClick), this);
 
         for (QAction* a : menu->actions()) {
-            QString aText = a->text().replace('&', "");
+            const std::string aText = a->text().replace('&', "").toStdString();
             GtkWidget* item;
             if (a->isSeparator())
                 item = gtk_menu_item_new();
             else if (a->icon().isNull())
-                item = gtk_menu_item_new_with_label(aText.toStdString().c_str());
+                item = gtk_menu_item_new_with_label(aText.c_str());
             else {
                 GdkPixbuf* pixbuf = convertQIconToPixbuf(a->icon());
-                item = gtk_image_menu_item_new_with_label(aText.toStdString().c_str());
+                item = gtk_image_menu_item_new_with_label(aText.c_str());
                 gtk_image_menu_item_set_image(GTK_IMAGE_MENU_ITEM(item),
                                               gtk_image_new_from_pixbuf(pixbuf));
                 gtk_image_menu_item_set_always_show_image(GTK_IMAGE_MENU_ITEM(item), TRUE);
@@ -174,15 +175,15 @@ void SystemTrayIcon::setContextMenu(QMenu* menu)
 #ifdef ENABLE_SYSTRAY_GTK_BACKEND
     else if (backendType == SystrayBackendType::GTK) {
         for (QAction* a : menu->actions()) {
-            QString aText = a->text().replace('&', "");
+            const std::string aText = a->text().replace('&', "").toStdString();
             GtkWidget* item;
             if (a->isSeparator())
                 item = gtk_menu_item_new();
             else if (a->icon().isNull())
-                item = gtk_menu_item_new_with_label(aText.toStdString().c_str());
+                item = gtk_menu_item_new_with_label(aText.c_str());
             else {
                 GdkPixbuf* pixbuf = convertQIconToPixbuf(a->icon());
-                item = gtk_image_menu_item_new_with_label(aText.toStdString().c_str());
+                item = gtk_image_menu_item_new_with_label(aText.c_str());
                 gtk_image_menu_item_set_image(GTK_IMAGE_MENU_ITEM(item),
                                               gtk_image_new_from_pixbuf(pixbuf));
                 gtk_image_menu_item_set_always_show_image(GTK_IMAGE_MENU_ITEM(item), TRUE);
@@ -206,16 +207,17 @@ void SystemTrayIcon::setContextMenu(QMenu* menu)
 #ifdef ENABLE_SYSTRAY_UNITY_BACKEND
     else if (backendType == SystrayBackendType::Unity) {
         for (QAction* a : menu->actions()) {
-            QString aText = a->text().replace('&', "");
+            const std::string aText = a->text().replace('&', "").toStdString();
             GtkWidget* item;
             if (a->isSeparator())
                 item = gtk_menu_item_new();
             else if (a->icon().isNull())
-                item = gtk_menu_item_new_with_label(aText.toStdString().c_str());
+                item = gtk_menu_item_new_with_label(aText.c_str());
             else {
-                QString iconPath = extractIconToFile(a->icon(), "iconmenu" + a->icon().name());
-                GtkWidget* image = gtk_image_new_from_file(iconPath.toStdString().c_str());
-                item = gtk_image_menu_item_new_with_label(aText.toStdString().c_str());
+                const std::string iconPath = extractIconToFile(a->icon(),
+                                             "iconmenu" + a->icon().name()).toStdString();
+                GtkWidget* image = gtk_image_new_from_file(iconPath.c_str());
+                item = gtk_image_menu_item_new_with_label(aText.c_str());
                 gtk_image_menu_item_set_image(GTK_IMAGE_MENU_ITEM(item), image);
                 gtk_image_menu_item_set_always_show_image(GTK_IMAGE_MENU_ITEM(item), TRUE);
             }