QPropertyAnimation reevaluates the default start value after each run

When the start value is not explicitly defined, the property animation
will set the default start to be the current property value when updating
the animation's state to Running.

Reviewed-by: Jan-Arve

1 files changed, 32 insertions, 0 deletions

diff --git a/tests/auto/qanimationgroup/tst_qanimationgroup.cpp b/tests/auto/qanimationgroup/tst_qanimationgroup.cpp
index 3cf56312ea..2952a391ef 100644
--- a/tests/auto/qanimationgroup/tst_qanimationgroup.cpp
+++ b/tests/auto/qanimationgroup/tst_qanimationgroup.cpp
@@ -69,6 +69,7 @@ private slots:
     void setParentAutoAdd();
     void beginNestedGroup();
     void addChildTwice();
+    void loopWithoutStartValue();
 };
 
 tst_QAnimationGroup::tst_QAnimationGroup()
@@ -377,5 +378,36 @@ void tst_QAnimationGroup::addChildTwice()
     delete parent;
 }
 
+void tst_QAnimationGroup::loopWithoutStartValue()
+{
+    QAnimationGroup *parent = new QSequentialAnimationGroup();
+    QObject o;
+    o.setProperty("ole", 0);
+    QCOMPARE(o.property("ole").toInt(), 0);
+
+    QPropertyAnimation anim1(&o, "ole");
+    anim1.setEndValue(-50);
+    anim1.setDuration(100);
+
+    QPropertyAnimation anim2(&o, "ole");
+    anim2.setEndValue(50);
+    anim2.setDuration(100);
+
+    parent->addAnimation(&anim1);
+    parent->addAnimation(&anim2);
+
+    parent->setLoopCount(-1);
+    parent->start();
+
+    QVERIFY(anim1.startValue().isNull());
+    QCOMPARE(anim1.currentValue().toInt(), 0);
+    QCOMPARE(parent->currentLoop(), 0);
+
+    parent->setCurrentTime(200);
+    QCOMPARE(parent->currentLoop(), 1);
+    QCOMPARE(anim1.currentValue().toInt(), 50);
+    parent->stop();
+}
+
 QTEST_MAIN(tst_QAnimationGroup)
 #include "tst_qanimationgroup.moc"