[QTBUG-27420] Make Q{Box,Grid,Form}Layout::takeAt() unparent a nested layout

QStackedLayout doesn't have support for QLayout, only QWidget, so
the issue doesn't arise there.

(cherry-picked from qtbase/716d33d2a73ade42eb31be3e8ecbaeecdd5ddd21)
(only change: s/reset()/clear()/ in the tests)

Reported-by: Johannes Schaub
Task-number: QTBUG-27420

Change-Id: I7f3c4b1996e954428c00d4dda1095712efa91367
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/tests/auto/qformlayout/tst_qformlayout.cpp b/tests/auto/qformlayout/tst_qformlayout.cpp
index 89c8f99..462992c 100644
--- a/tests/auto/qformlayout/tst_qformlayout.cpp
+++ b/tests/auto/qformlayout/tst_qformlayout.cpp
@@ -50,6 +50,7 @@
 
 #include <QtGui/QWindowsStyle>
 #include <QStyleFactory>
+#include <QSharedPointer>
 
 #include <qformlayout.h>
 
@@ -125,6 +126,8 @@ private slots:
     Qt::Orientations expandingDirections() const;
 */
 
+    void taskQTBUG_27420_takeAtShouldUnparentLayout();
+
 };
 
 tst_QFormLayout::tst_QFormLayout()
@@ -905,6 +908,27 @@ void tst_QFormLayout::layoutAlone()
     QTest::qWait(500);
 }
 
+void tst_QFormLayout::taskQTBUG_27420_takeAtShouldUnparentLayout()
+{
+    QSharedPointer<QFormLayout> outer(new QFormLayout);
+    QPointer<QFormLayout> inner = new QFormLayout;
+
+    outer->addRow(inner);
+    QCOMPARE(outer->count(), 1);
+    QCOMPARE(inner->parent(), outer.data());
+
+    QLayoutItem *item = outer->takeAt(0);
+    QCOMPARE(item->layout(), inner.data());
+    QVERIFY(!item->layout()->parent());
+
+    outer.clear();
+
+    if (inner)
+        delete item; // success: a taken item/layout should not be deleted when the old parent is deleted
+    else
+        QVERIFY(!inner.isNull());
+}
+
 QTEST_MAIN(tst_QFormLayout)
 
 #include "tst_qformlayout.moc"