Fixed QLayout::addChildLayout(QLayout *l) when l had a parent

Previously if l had a parent, addChildLayout would warn and skip the
reparenting, but it would still add the sub layout to the layout.
This caused some inconsistencies in the hierarchy which in worst case
could cause crashes.

Task-number: QTBUG-30758
Change-Id: I618ec3341636b97bd71e421201b22c746dcf43e1
Reviewed-by: Paul Olav Tvete <paul.tvete@digia.com>

1 files changed, 21 insertions, 0 deletions

diff --git a/tests/auto/widgets/kernel/qboxlayout/tst_qboxlayout.cpp b/tests/auto/widgets/kernel/qboxlayout/tst_qboxlayout.cpp
index 227a31b10d..84d796f657 100644
--- a/tests/auto/widgets/kernel/qboxlayout/tst_qboxlayout.cpp
+++ b/tests/auto/widgets/kernel/qboxlayout/tst_qboxlayout.cpp
@@ -68,6 +68,7 @@ public slots:
 
 private slots:
     void insertSpacerItem();
+    void insertLayout();
     void sizeHint();
     void sizeConstraints();
     void setGeometry();
@@ -166,6 +167,26 @@ void tst_QBoxLayout::insertSpacerItem()
     window->show();
 }
 
+void tst_QBoxLayout::insertLayout()
+{
+    QWidget *window = new QWidget;
+    QVBoxLayout *vbox = new QVBoxLayout(window);
+    QVBoxLayout *dummyParentLayout = new QVBoxLayout;
+    QHBoxLayout *subLayout = new QHBoxLayout;
+    dummyParentLayout->addLayout(subLayout);
+    QCOMPARE(subLayout->parent(), dummyParentLayout);
+    QCOMPARE(dummyParentLayout->count(), 1);
+
+    // add subLayout to another layout
+    QTest::ignoreMessage(QtWarningMsg, "QLayout::addChildLayout: layout \"\" already has a parent");
+    vbox->addLayout(subLayout);
+    QCOMPARE((subLayout->parent() == vbox), (vbox->count() == 1));
+
+    delete dummyParentLayout;
+    delete window;
+}
+
+
 void tst_QBoxLayout::sizeHint()
 {
     QWidget *window = new QWidget;