From a7ef2d899d711d750238a8d69284da808188b407 Mon Sep 17 00:00:00 2001
From: Yoann Lopes <yoann.lopes@nokia.com>
Date: Wed, 17 Feb 2010 13:47:26 +0100
Subject: Fixes crash when destroying a QGraphicsItem.

When clearing the focus on an item, the focus was previously passed to
the closest parent focus scope (if any). But the focus should go to the
closest parent focus scope only if the item being cleared of the focus
is itself a focus scope. This incorrect behavior leaded to invalid
pointers in QGraphicsItem under specific circumstances, eventually
leading to a crash when destroying the item.

Auto-test included.

Task-number: QT-2649
Reviewed-by: Andreas Aardal Hanssen
---
 src/gui/graphicsview/qgraphicsitem.cpp         |  5 ++-
 tests/auto/qgraphicsitem/tst_qgraphicsitem.cpp | 57 ++++++++++++++++++++++++++
 2 files changed, 60 insertions(+), 2 deletions(-)

diff --git a/src/gui/graphicsview/qgraphicsitem.cpp b/src/gui/graphicsview/qgraphicsitem.cpp
index 63b0ec7..54914b3 100644
--- a/src/gui/graphicsview/qgraphicsitem.cpp
+++ b/src/gui/graphicsview/qgraphicsitem.cpp
@@ -3174,8 +3174,9 @@ void QGraphicsItemPrivate::setFocusHelper(Qt::FocusReason focusReason, bool clim
 */
 void QGraphicsItem::clearFocus()
 {
-    // Pass focus to the closest parent focus scope.
-    if (!d_ptr->inDestructor) {
+    // Pass focus to the closest parent focus scope when clearing focus
+    // from a focus scope.
+    if (!d_ptr->inDestructor && (d_ptr->flags & ItemIsFocusScope)) {
         QGraphicsItem *p = d_ptr->parent;
         while (p) {
             if (p->flags() & ItemIsFocusScope) {
diff --git a/tests/auto/qgraphicsitem/tst_qgraphicsitem.cpp b/tests/auto/qgraphicsitem/tst_qgraphicsitem.cpp
index 7c1b97e..269ec24 100644
--- a/tests/auto/qgraphicsitem/tst_qgraphicsitem.cpp
+++ b/tests/auto/qgraphicsitem/tst_qgraphicsitem.cpp
@@ -438,6 +438,7 @@ private slots:
     void QTBUG_6738_missingUpdateWithSetParent();
     void QTBUG_7714_fullUpdateDiscardingOpacityUpdate2();
     void QT_2653_fullUpdateDiscardingOpacityUpdate();
+    void QT_2649_focusScope();
 
 private:
     QList<QGraphicsItem *> paintedItems;
@@ -10002,5 +10003,61 @@ void tst_QGraphicsItem::QTBUG_7714_fullUpdateDiscardingOpacityUpdate2()
     QTRY_COMPARE(view.repaints, 1);
 }
 
+void tst_QGraphicsItem::QT_2649_focusScope()
+{
+    QGraphicsScene *scene = new QGraphicsScene;
+
+    QGraphicsRectItem *subFocusItem = new QGraphicsRectItem;
+    subFocusItem->setFlags(QGraphicsItem::ItemIsFocusable);
+    subFocusItem->setFocus();
+    QCOMPARE(subFocusItem->focusItem(), (QGraphicsItem *)subFocusItem);
+
+    QGraphicsRectItem *scope = new QGraphicsRectItem;
+    scope->setFlags(QGraphicsItem::ItemIsFocusable | QGraphicsItem::ItemIsFocusScope);
+    scope->setFocus();
+    subFocusItem->setParentItem(scope);
+    QCOMPARE(subFocusItem->focusItem(), (QGraphicsItem *)subFocusItem);
+    QCOMPARE(subFocusItem->focusScopeItem(), (QGraphicsItem *)0);
+    QCOMPARE(scope->focusItem(), (QGraphicsItem *)subFocusItem);
+    QCOMPARE(scope->focusScopeItem(), (QGraphicsItem *)subFocusItem);
+
+    QGraphicsRectItem *rootItem = new QGraphicsRectItem;
+    rootItem->setFlags(QGraphicsItem::ItemIsFocusable);
+    scope->setParentItem(rootItem);
+    QCOMPARE(rootItem->focusItem(), (QGraphicsItem *)subFocusItem);
+    QCOMPARE(rootItem->focusScopeItem(), (QGraphicsItem *)0);
+    QCOMPARE(subFocusItem->focusItem(), (QGraphicsItem *)subFocusItem);
+    QCOMPARE(subFocusItem->focusScopeItem(), (QGraphicsItem *)0);
+    QCOMPARE(scope->focusItem(), (QGraphicsItem *)subFocusItem);
+    QCOMPARE(scope->focusScopeItem(), (QGraphicsItem *)subFocusItem);
+
+    scene->addItem(rootItem);
+
+    QEvent windowActivate(QEvent::WindowActivate);
+    qApp->sendEvent(scene, &windowActivate);
+    scene->setFocus();
+
+    QCOMPARE(rootItem->focusItem(), (QGraphicsItem *)subFocusItem);
+    QCOMPARE(scope->focusItem(), (QGraphicsItem *)subFocusItem);
+    QCOMPARE(subFocusItem->focusItem(), (QGraphicsItem *)subFocusItem);
+    QCOMPARE(rootItem->focusScopeItem(), (QGraphicsItem *)0);
+    QCOMPARE(scope->focusScopeItem(), (QGraphicsItem *)subFocusItem);
+    QCOMPARE(subFocusItem->focusScopeItem(), (QGraphicsItem *)0);
+    QVERIFY(subFocusItem->hasFocus());
+
+    //If we hide the focusScope, the entire subFocus chain should be cleared
+    scope->hide();
+
+    QCOMPARE(rootItem->focusItem(), (QGraphicsItem *)0);
+    QCOMPARE(scope->focusItem(), (QGraphicsItem *)0);
+    QCOMPARE(subFocusItem->focusItem(), (QGraphicsItem *)0);
+    QCOMPARE(rootItem->focusScopeItem(), (QGraphicsItem *)0);
+    QCOMPARE(scope->focusScopeItem(), (QGraphicsItem *)subFocusItem);
+    QCOMPARE(subFocusItem->focusScopeItem(), (QGraphicsItem *)0);
+    QVERIFY(!subFocusItem->hasFocus());
+
+    delete scene;
+}
+
 QTEST_MAIN(tst_QGraphicsItem)
 #include "tst_qgraphicsitem.moc"
-- 
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