Client xdg-shell v5: Fix crash when creating a popup without a valid parent

Fixes: QTBUG-72696
Change-Id: I43f0a02a4447238aa93142981d22597c452790fd
Reviewed-by: Paul Olav Tvete <paul.tvete@qt.io>

2 files changed, 12 insertions, 4 deletions

diff --git a/src/plugins/shellintegration/xdg-shell-v5/qwaylandxdgshellv5.cpp b/src/plugins/shellintegration/xdg-shell-v5/qwaylandxdgshellv5.cpp
index 4cbafbd7..3eda43d7 100644
--- a/src/plugins/shellintegration/xdg-shell-v5/qwaylandxdgshellv5.cpp
+++ b/src/plugins/shellintegration/xdg-shell-v5/qwaylandxdgshellv5.cpp
@@ -71,6 +71,9 @@ QWaylandXdgSurfaceV5 *QWaylandXdgShellV5::createXdgSurface(QWaylandWindow *windo
 QWaylandXdgPopupV5 *QWaylandXdgShellV5::createXdgPopup(QWaylandWindow *window, QWaylandInputDevice *inputDevice)
 {
     QWaylandWindow *parentWindow = m_popups.empty() ? window->transientParent() : m_popups.last();
+    if (!parentWindow)
+        return nullptr;
+
     ::wl_surface *parentSurface = parentWindow->object();
 
     if (m_popupSerial == 0)
diff --git a/src/plugins/shellintegration/xdg-shell-v5/qwaylandxdgshellv5integration.cpp b/src/plugins/shellintegration/xdg-shell-v5/qwaylandxdgshellv5integration.cpp
index 12cc95b1..410f2700 100644
--- a/src/plugins/shellintegration/xdg-shell-v5/qwaylandxdgshellv5integration.cpp
+++ b/src/plugins/shellintegration/xdg-shell-v5/qwaylandxdgshellv5integration.cpp
@@ -73,10 +73,15 @@ bool QWaylandXdgShellV5Integration::initialize(QWaylandDisplay *display)
 QWaylandShellSurface *QWaylandXdgShellV5Integration::createShellSurface(QWaylandWindow *window)
 {
     QWaylandInputDevice *inputDevice = window->display()->lastInputDevice();
-    if (window->window()->type() == Qt::WindowType::Popup && inputDevice)
-        return m_xdgShell->createXdgPopup(window, inputDevice);
-    else
-        return m_xdgShell->createXdgSurface(window);
+    if (window->window()->type() == Qt::WindowType::Popup && inputDevice) {
+        if (auto *popup = m_xdgShell->createXdgPopup(window, inputDevice))
+            return popup;
+
+        qWarning(lcQpaWayland) << "Failed to create xdg-popup v5 for window" << window->window()
+                               << "falling back to creating an xdg-surface";
+    }
+
+    return m_xdgShell->createXdgSurface(window);
 }
 
 void QWaylandXdgShellV5Integration::handleKeyboardFocusChanged(QWaylandWindow *newFocus, QWaylandWindow *oldFocus) {