window: unassign surface on unmap

src/Window.cpp

@@ -336,6 +336,8 @@ void CWindow::onUnmap() {
     m_vRealSize.setCallbackOnBegin(nullptr);
 
     std::erase_if(g_pCompositor->m_vWindowFocusHistory, [&](const auto& other) { return other == this; });
+
+    m_pWLSurface.unassign();
 }
 
 void CWindow::onMap() {

src/helpers/WLSurface.cpp

@@ -11,6 +11,10 @@ void CWLSurface::assign(wlr_surface* pSurface) {
     init();
 }
 
+void CWLSurface::unassign() {
+    destroy();
+}
+
 CWLSurface::~CWLSurface() {
     destroy();
 }

src/helpers/WLSurface.hpp

@@ -9,6 +9,7 @@ class CWLSurface {
     ~CWLSurface();
 
     void assign(wlr_surface* pSurface);
+    void unassign();
 
     CWLSurface(const CWLSurface&) = delete;
     CWLSurface(CWLSurface&&)      = delete;