QQuickAnimatorJob: store the target with a QPointer

This avoids ending up with invalid pointers when under some circumstances the
target (which is not owned by the QQuickAnimatorJob) is destroyed between the
time the QQuickAnimatorJob is created and the time it is initialized. This is
the case when the target of an Animator is the item loaded by a Loader and
that the animator is started just before setting the Loader to inactive.

Also added an auto test for that special case.

Task-number: QTBUG-49634
Change-Id: Iab9bfe76d13755ba735432c6f97bde175d308814
Reviewed-by: Thomas McGuire <thomas.mcguire@kdab.com>
Reviewed-by: Gunnar Sletta <gunnar@sletta.org>

2 files changed, 78 insertions, 0 deletions

diff --git a/tests/auto/quick/qquickanimations/data/animatorInvalidTargetCrash.qml b/tests/auto/quick/qquickanimations/data/animatorInvalidTargetCrash.qml
new file mode 100644
index 0000000000..f2c378e4b5
--- /dev/null
+++ b/tests/auto/quick/qquickanimations/data/animatorInvalidTargetCrash.qml
@@ -0,0 +1,63 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 Klaralvdalens Datakonsult AB (KDAB).
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the QtQuick module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL21$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 or version 3 as published by the Free
+** Software Foundation and appearing in the file LICENSE.LGPLv21 and
+** LICENSE.LGPLv3 included in the packaging of this file. Please review the
+** following information to ensure the GNU Lesser General Public License
+** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** As a special exception, The Qt Company gives you certain additional
+** rights. These rights are described in The Qt Company LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+import QtQuick 2.3
+import QtQuick.Window 2.2
+
+Window {
+    visible: true
+    width: 100
+    height: 100
+
+    OpacityAnimator {
+        id: anim
+        from: 1
+        to:0
+        duration: 5000
+        running: false
+    }
+
+    Loader {
+        id: loader
+        sourceComponent: Text {
+            text: "Hello World"
+            anchors.centerIn: parent
+        }
+    }
+
+    Component.onCompleted: {
+        anim.target = loader.item;
+        anim.start();
+        loader.active = false;
+    }
+}
diff --git a/tests/auto/quick/qquickanimations/tst_qquickanimations.cpp b/tests/auto/quick/qquickanimations/tst_qquickanimations.cpp
index 2b805e9eeb..d234cd2d94 100644
--- a/tests/auto/quick/qquickanimations/tst_qquickanimations.cpp
+++ b/tests/auto/quick/qquickanimations/tst_qquickanimations.cpp
@@ -104,6 +104,7 @@ private slots:
     void scriptActionBug();
     void groupAnimationNullChildBug();
     void scriptActionCrash();
+    void animatorInvalidTargetCrash();
 };
 
 #define QTIMED_COMPARE(lhs, rhs) do { \
@@ -1491,7 +1492,21 @@ void tst_qquickanimations::scriptActionCrash()
     delete obj;
 }
 
+// QTBUG-49364
+// Test that we don't crash when the target of an Animator becomes
+// invalid between the time the animator is started and the time the
+// animator job is actually started
+void tst_qquickanimations::animatorInvalidTargetCrash()
+{
+    QQmlEngine engine;
+    QQmlComponent c(&engine, testFileUrl("animatorInvalidTargetCrash.qml"));
+    QObject *obj = c.create();
 
+    //just testing that we don't crash
+    QTest::qWait(5000); //animator duration
+
+    delete obj;
+}
 
 QTEST_MAIN(tst_qquickanimations)