window: fix empty masks not applying

src/core/proxywindow.cpp

@@ -1,5 +1,6 @@
 #include "proxywindow.hpp"
 
+#include <qnamespace.h>
 #include <qobject.h>
 #include <qqmlengine.h>
 #include <qqmllist.h>
@@ -215,6 +216,12 @@ void ProxyWindowBase::updateMask() {
 			auto windowRegion = QRegion(QRect(0, 0, this->width(), this->height()));
 			mask = this->mMask->applyTo(windowRegion);
 		}
+
+		if (mask.isEmpty()) {
+			this->window->setFlag(Qt::WindowTransparentForInput, true);
+		}
+	} else {
+		this->window->setFlag(Qt::WindowTransparentForInput, false);
 	}
 
 	this->window->setMask(mask);