Force clear clipboard on Wayland

* Fixes #4498

src/gui/Clipboard.cpp

@@ -21,6 +21,7 @@
 #include <QApplication>
 #include <QClipboard>
 #include <QMimeData>
+#include <QProcess>
 #include <QTimer>
 
 #include "core/Config.h"
@@ -101,6 +102,12 @@ void Clipboard::clearCopiedText()
         || m_lastCopied == clipboard->text(QClipboard::Selection)) {
         clipboard->clear(QClipboard::Clipboard);
         clipboard->clear(QClipboard::Selection);
+#ifdef Q_OS_UNIX
+        // Gnome Wayland doesn't let apps modify the clipboard when not in focus, so force clear
+        if (QProcessEnvironment::systemEnvironment().contains("WAYLAND_DISPLAY")) {
+            QProcess::startDetached("wl-copy", {"-c"});
+        }
+#endif
     }
 
     m_lastCopied.clear();