Replace manual parent traversal in isWindowBlocked with use of isAncestorOf

Change-Id: I208d70a61e407069277339b3997c82921ab1b39b
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>

1 files changed, 5 insertions, 13 deletions

diff --git a/src/gui/kernel/qguiapplication.cpp b/src/gui/kernel/qguiapplication.cpp
index e0eff166a8..72433b56a5 100644
--- a/src/gui/kernel/qguiapplication.cpp
+++ b/src/gui/kernel/qguiapplication.cpp
@@ -818,19 +818,11 @@ bool QGuiApplicationPrivate::isWindowBlocked(QWindow *window, QWindow **blocking
     for (int i = 0; i < modalWindowList.count(); ++i) {
         QWindow *modalWindow = modalWindowList.at(i);
 
-        {
-            // check if the modal window is our window or a (transient) parent of our window
-            QWindow *w = window;
-            while (w) {
-                if (w == modalWindow) {
-                    *blockingWindow = 0;
-                    return false;
-                }
-                QWindow *p = w->parent();
-                if (!p)
-                    p = w->transientParent();
-                w = p;
-            }
+        // A window is not blocked by another modal window if the two are
+        // the same, or if the window is a child of the modal window.
+        if (window == modalWindow || modalWindow->isAncestorOf(window, QWindow::IncludeTransients)) {
+            *blockingWindow = 0;
+            return false;
         }
 
         Qt::WindowModality windowModality = modalWindow->modality();