Fix WebUI error handling

src/app/application.cpp

@@ -146,6 +146,13 @@ Application::Application(const QString &id, int &argc, char **argv)
     Logger::instance()->addMessage(tr("qBittorrent %1 started", "qBittorrent v3.2.0alpha started").arg(QBT_VERSION));
 }
 
+Application::~Application()
+{
+    // we still need to call cleanup()
+    // in case the App failed to start
+    cleanup();
+}
+
 #ifndef DISABLE_GUI
 QPointer<MainWindow> Application::mainWindow()
 {
@@ -483,7 +490,12 @@ int Application::exec(const QStringList &params)
 
 #ifndef DISABLE_WEBUI
     m_webui = new WebUI;
-#endif
+#ifdef DISABLE_GUI
+    if (m_webui->isErrored())
+        return 1;
+    connect(m_webui, &WebUI::fatalError, this, []() { QCoreApplication::exit(1); });
+#endif // DISABLE_GUI
+#endif // DISABLE_WEBUI
 
     new RSS::Session; // create RSS::Session singleton
     new RSS::AutoDownloader; // create RSS::AutoDownloader singleton
@@ -642,14 +654,13 @@ void Application::shutdownCleanup(QSessionManager &manager)
 
 void Application::cleanup()
 {
-#ifndef DISABLE_GUI
-#ifdef Q_OS_WIN
     // cleanup() can be called multiple times during shutdown. We only need it once.
     static QAtomicInt alreadyDone;
     if (!alreadyDone.testAndSetAcquire(0, 1))
         return;
-#endif // Q_OS_WIN
 
+#ifndef DISABLE_GUI
+    if (m_window) {
         // Hide the window and not leave it on screen as
         // unresponsive. Also for Windows take the WinId
         // after it's hidden, because hide() may cause a
@@ -672,7 +683,7 @@ void Application::cleanup()
         // otherwise the system shutdown will continue even
         // though we created a ShutdownBlockReason
         m_window->cleanup();
-
+    }
 #endif // DISABLE_GUI
 
 #ifndef DISABLE_WEBUI
@@ -697,6 +708,7 @@ void Application::cleanup()
     Utils::Fs::removeDirRecursive(Utils::Fs::tempPath());
 
 #ifndef DISABLE_GUI
+    if (m_window) {
 #ifdef Q_OS_WIN
         typedef BOOL (WINAPI *PSHUTDOWNBRDESTROY)(HWND);
         PSHUTDOWNBRDESTROY shutdownBRDestroy = (PSHUTDOWNBRDESTROY)::GetProcAddress(::GetModuleHandleW(L"User32.dll"), "ShutdownBlockReasonDestroy");
@@ -705,6 +717,7 @@ void Application::cleanup()
             shutdownBRDestroy((HWND)m_window->effectiveWinId());
 #endif // Q_OS_WIN
         delete m_window;
+    }
 #endif // DISABLE_GUI
 
     if (m_shutdownAct != ShutdownDialogAction::Exit) {

src/app/application.h

@@ -73,9 +73,11 @@ namespace RSS
 class Application : public BaseApplication
 {
     Q_OBJECT
+    Q_DISABLE_COPY(Application)
 
 public:
     Application(const QString &id, int &argc, char **argv);
+    ~Application() override;
 
  #if (defined(Q_OS_WIN) && !defined(DISABLE_GUI))
     bool isRunning();
@@ -132,7 +134,7 @@ private:
 #endif
 
 #ifndef DISABLE_WEBUI
-    QPointer<WebUI> m_webui;
+    WebUI *m_webui;
 #endif
 
     // FileLog

src/webui/webui.cpp

@@ -28,10 +28,6 @@
 
 #include "webui.h"
 
-#ifdef DISABLE_GUI
-#include <QCoreApplication>
-#endif
-
 #include "base/http/server.h"
 #include "base/logger.h"
 #include "base/net/dnsupdater.h"
@@ -39,18 +35,20 @@
 #include "base/preferences.h"
 #include "webapplication.h"
 
-WebUI::WebUI(QObject *parent)
-    : QObject(parent)
+WebUI::WebUI()
+    : m_isErrored(false)
     , m_port(0)
 {
-    init();
-    connect(Preferences::instance(), SIGNAL(changed()), SLOT(init()));
+    configure();
+    connect(Preferences::instance(), &Preferences::changed, this, &WebUI::configure);
 }
 
-void WebUI::init()
+void WebUI::configure()
 {
-    Logger* const logger = Logger::instance();
-    Preferences* const pref = Preferences::instance();
+    m_isErrored = false; // clear previous error state
+
+    Logger *const logger = Logger::instance();
+    Preferences *const pref = Preferences::instance();
 
     const quint16 oldPort = m_port;
     m_port = pref->getWebUiPort();
@@ -105,10 +103,10 @@ void WebUI::init()
                 const QString errorMsg = tr("Web UI: Unable to bind to IP: %1, port: %2. Reason: %3")
                     .arg(serverAddressString).arg(m_port).arg(m_httpServer->errorString());
                 logger->addMessage(errorMsg, Log::CRITICAL);
-#ifdef DISABLE_GUI
                 qCritical() << errorMsg;
-                QCoreApplication::exit(1);
-#endif
+
+                m_isErrored = true;
+                emit fatalError();
             }
         }
 
@@ -137,3 +135,8 @@ void WebUI::init()
             delete m_dnsUpdater;
     }
 }
+
+bool WebUI::isErrored() const
+{
+    return m_isErrored;
+}

src/webui/webui.h

@@ -47,14 +47,21 @@ class AbstractWebApplication;
 class WebUI : public QObject
 {
     Q_OBJECT
+    Q_DISABLE_COPY(WebUI)
 
 public:
-    explicit WebUI(QObject *parent = 0);
+    WebUI();
+
+    bool isErrored() const;
+
+signals:
+    void fatalError();
 
 private slots:
-    void init();
+    void configure();
 
 private:
+    bool m_isErrored;
     QPointer<Http::Server> m_httpServer;
     QPointer<Net::DNSUpdater> m_dnsUpdater;
     QPointer<AbstractWebApplication> m_webapp;