--- ownCloud-2.9.0.5150.unchanged/src/gui/CMakeLists.txt	2021-09-08 16:45:51.000000000 +0200
+++ ownCloud-2.9.0.5150/src/gui/CMakeLists.txt	2021-09-24 14:10:14.388796420 +0200
@@ -102,18 +102,8 @@ set(client_SRCS
 
 set(3rdparty_SRC
     ../3rdparty/QProgressIndicator/QProgressIndicator.cpp
-    ../3rdparty/qtlockedfile/qtlockedfile.cpp
-    ../3rdparty/qtsingleapplication/qtlocalpeer.cpp
-    ../3rdparty/qtsingleapplication/qtsingleapplication.cpp
-    ../3rdparty/qtsingleapplication/qtsinglecoreapplication.cpp
    )
 
-if(NOT WIN32)
-   list(APPEND 3rdparty_SRC ../3rdparty/qtlockedfile/qtlockedfile_unix.cpp)
-else()
-   list(APPEND 3rdparty_SRC ../3rdparty/qtlockedfile/qtlockedfile_win.cpp )
-endif()
-
 set( final_src
     ${MIRALL_RC_SRC}
     ${client_SRCS}
@@ -128,14 +118,12 @@ endif()
 add_library(owncloudCore STATIC ${final_src})
 set_target_properties(owncloudCore PROPERTIES AUTOUIC ON AUTORCC ON)
 target_link_libraries(owncloudCore PUBLIC Qt5::Widgets Qt5::Network Qt5::Xml
-                                          libsync)
+                                          libsync Qt5Solutions_LockedFile-2.4 Qt5Solutions_SingleApplication-2.6)
 
 add_subdirectory(socketapi)
 
 target_include_directories(owncloudCore PUBLIC
     ${CMAKE_SOURCE_DIR}/src/3rdparty/QProgressIndicator
-    ${CMAKE_SOURCE_DIR}/src/3rdparty/qtlockedfile
-    ${CMAKE_SOURCE_DIR}/src/3rdparty/qtsingleapplication
     ${CMAKE_CURRENT_BINARY_DIR}
 )
 
--- ownCloud-2.9.0.5150.unchanged/src/gui/application.cpp	2021-09-08 16:45:51.000000000 +0200
+++ ownCloud-2.9.0.5150/src/gui/application.cpp	2021-09-24 14:18:52.528770199 +0200
@@ -211,7 +211,7 @@ ownCloudGui *Application::gui() const
 }
 
 Application::Application(int &argc, char **argv)
-    : SharedTools::QtSingleApplication(Theme::instance()->appName(), argc, argv)
+    : QtSingleApplication(Theme::instance()->appName(), argc, argv)
     , _gui(nullptr)
     , _theme(Theme::instance())
     , _logExpire(0)
@@ -291,7 +291,7 @@ Application::Application(int &argc, char
 
     _folderManager.reset(new FolderMan);
 
-    connect(this, &SharedTools::QtSingleApplication::messageReceived, this, &Application::slotParseMessage);
+    connect(this, &QtSingleApplication::messageReceived, this, &Application::slotParseMessage);
 
     if (!AccountManager::instance()->restore()) {
         // If there is an error reading the account settings, try again
@@ -533,7 +533,7 @@ void Application::slotUseMonoIconsChange
     _gui->slotComputeOverallSyncStatus();
 }
 
-void Application::slotParseMessage(const QString &msg, QObject *)
+void Application::slotParseMessage(const QString &msg)
 {
     if (msg.startsWith(QLatin1String("MSG_PARSEOPTIONS:"))) {
         const int lengthOfMsgPrefix = 17;
@@ -813,7 +813,7 @@ bool Application::event(QEvent *event)
         QTimer::singleShot(0, this, [this, fn] { openVirtualFile(fn); });
     }
 #endif
-    return SharedTools::QtSingleApplication::event(event);
+    return QtSingleApplication::event(event);
 }
 
 } // namespace OCC
--- ownCloud-2.9.0.5150.unchanged/src/gui/application.h	2021-09-08 16:45:51.000000000 +0200
+++ ownCloud-2.9.0.5150/src/gui/application.h	2021-09-24 14:21:45.241593261 +0200
@@ -20,8 +20,7 @@
 #include <QQueue>
 #include <QTimer>
 #include <QNetworkConfigurationManager>
-
-#include "3rdparty/qtsingleapplication/qtsingleapplication.h"
+#include <QtSolutions/qtsingleapplication.h>
 
 #include "syncresult.h"
 #include "logbrowser.h"
@@ -51,7 +50,7 @@ class SslErrorDialog;
  * @brief The Application class
  * @ingroup gui
  */
-class Application : public SharedTools::QtSingleApplication
+class Application : public QtSingleApplication
 {
     Q_OBJECT
 public:
@@ -93,7 +92,7 @@ signals:
     void folderStateChanged(Folder *);
 
 protected slots:
-    void slotParseMessage(const QString &, QObject *);
+    void slotParseMessage(const QString &);
     void slotCheckConnection();
     void slotUseMonoIconsChanged(bool);
     void slotCleanup();