Revert "Qt: fix memory leaks found by Visual Leak Detector"

This reverts commit c2edb44a9a.

While we should definitely avoid leaking memory, this runs up against
the Qt code's assumption that it will always have valid epan data.

Fixes #17590.
Fixes #17719.

ui/qt/funnel_statistics.cpp

@@ -155,8 +155,13 @@ FunnelStatistics::FunnelStatistics(QObject *parent, CaptureFile &cf) :
 
 FunnelStatistics::~FunnelStatistics()
 {
-    delete(funnel_ops_id_);
-    delete(funnel_ops_);
+    // At this point we're probably closing the program and will shortly
+    // call epan_cleanup, which calls ProgDlg__gc and TextWindow__gc.
+    // They in turn depend on funnel_ops_ being valid.
+    memset(funnel_ops_id_, 0, sizeof(struct _funnel_ops_id_t));
+    memset(funnel_ops_, 0, sizeof(struct _funnel_ops_t));
+    // delete(funnel_ops_id_);
+    // delete(funnel_ops_);
 }
 
 void FunnelStatistics::retapPackets()

ui/qt/main.cpp

@@ -680,7 +680,7 @@ int main(int argc, char *qt_argv[])
 #endif
 
     /* Create The Wireshark app */
-    wsApp = new WiresharkApplication(argc, qt_argv);
+    WiresharkApplication ws_app(argc, qt_argv);
 
     /* initialize the funnel mini-api */
     // xxx qtshark
@@ -724,9 +724,9 @@ int main(int argc, char *qt_argv[])
     main_w->show();
     // We may not need a queued connection here but it would seem to make sense
     // to force the issue.
-    main_w->connect(wsApp, SIGNAL(openCaptureFile(QString,QString,unsigned int)),
+    main_w->connect(&ws_app, SIGNAL(openCaptureFile(QString,QString,unsigned int)),
             main_w, SLOT(openCaptureFile(QString,QString,unsigned int)));
-    main_w->connect(wsApp, SIGNAL(openCaptureOptions()),
+    main_w->connect(&ws_app, SIGNAL(openCaptureOptions()),
             main_w, SLOT(on_actionCaptureOptions_triggered()));
 
     /* Init the "Open file" dialog directory */
@@ -819,7 +819,7 @@ int main(int argc, char *qt_argv[])
     ws_log(LOG_DOMAIN_MAIN, LOG_LEVEL_INFO, "Calling module preferences, elapsed time %" G_GUINT64_FORMAT " us \n", g_get_monotonic_time() - start_time);
 #endif
 
-    global_commandline_info.prefs_p = wsApp->readConfigurationFiles(false);
+    global_commandline_info.prefs_p = ws_app.readConfigurationFiles(false);
 
     /* Now get our args */
     commandline_other_options(argc, argv, TRUE);
@@ -1049,13 +1049,11 @@ int main(int argc, char *qt_argv[])
     profile_store_persconffiles(FALSE);
 
     ret_val = wsApp->exec();
-
-    recent_cleanup();
-    epan_cleanup();
+    wsApp = NULL;
 
     delete main_w;
-    delete wsApp;
-    wsApp = NULL;
+    recent_cleanup();
+    epan_cleanup();
 
     extcap_cleanup();
 

ui/qt/packet_diagram.cpp

@@ -523,7 +523,7 @@ void PacketDiagram::resetScene(bool reset_root)
     if (scene()) {
         delete scene();
     }
-    QGraphicsScene *new_scene = new QGraphicsScene(this);
+    QGraphicsScene *new_scene = new QGraphicsScene();
     setScene(new_scene);
     connect(new_scene, &QGraphicsScene::selectionChanged, this, &PacketDiagram::sceneSelectionChanged);
     setRootNode(reset_root ? nullptr : root_node_);

ui/qt/wireshark_application.cpp

@@ -629,6 +629,7 @@ WiresharkApplication::WiresharkApplication(int &argc,  char **argv) :
     if_notifier_(NULL),
     active_captures_(0)
 {
+    wsApp = this;
     setApplicationName("Wireshark");
 
     MimeDatabaseInitThread *mime_db_init_thread = new(MimeDatabaseInitThread);
@@ -778,6 +779,7 @@ WiresharkApplication::WiresharkApplication(int &argc,  char **argv) :
 
 WiresharkApplication::~WiresharkApplication()
 {
+    wsApp = NULL;
     clearDynamicMenuGroupItems();
     free_filter_lists();
 }