layershell: fix protocol error on popup attachment

default.nix

@@ -26,7 +26,7 @@
 }: stdenv.mkDerivation {
   pname = "quickshell${lib.optionalString debug "-debug"}";
   version = "0.1.0";
-  src = nix-gitignore.gitignoreSource [] ./.;
+  src = nix-gitignore.gitignoreSource "/docs\n/examples\n" ./.;
 
   nativeBuildInputs = with pkgs; [
     cmake

docs

@@ -1 +1 @@
-Subproject commit 70989dc619bcdc29dc4880b4ff5257d6ad188a18
+Subproject commit b218d3ec30f8ff2c51d4caf17509b9d21cf0c088

src/wayland/wlr_layershell/surface.cpp

@@ -1,4 +1,5 @@
 #include "surface.hpp"
+#include <any>
 
 #include <private/qwaylanddisplay_p.h>
 #include <private/qwaylandscreen_p.h>
@@ -165,3 +166,14 @@ QSize constrainedSize(const Anchors& anchors, const QSize& size) noexcept {
 	    anchors.verticalConstraint() ? 0 : size.height()
 	);
 }
+
+void QSWaylandLayerSurface::attachPopup(QtWaylandClient::QWaylandShellSurface* popup) {
+	std::any role = popup->surfaceRole();
+
+	if (auto* popupRole = std::any_cast<::xdg_popup*>(&role)) { // NOLINT
+		this->get_popup(*popupRole);
+	} else {
+		qWarning() << "Cannot attach popup" << popup << "to shell surface" << this
+		           << "as the popup is not an xdg_popup.";
+	}
+}

src/wayland/wlr_layershell/surface.hpp

@@ -27,6 +27,8 @@ public:
 	void applyConfigure() override;
 	void setWindowGeometry(const QRect& geometry) override;
 
+	void attachPopup(QtWaylandClient::QWaylandShellSurface* popup) override;
+
 private:
 	void zwlr_layer_surface_v1_configure(quint32 serial, quint32 width, quint32 height) override;
 	void zwlr_layer_surface_v1_closed() override;