Avoid interpolating if we have less than 2 key values in QVariantAnimation

If we have less than 2 key values, we should neither try to interpolate
nor set the current value.

Reviewed-by: janarve

1 files changed, 31 insertions, 0 deletions

diff --git a/tests/auto/qpropertyanimation/tst_qpropertyanimation.cpp b/tests/auto/qpropertyanimation/tst_qpropertyanimation.cpp
index 172950f..c753477 100644
--- a/tests/auto/qpropertyanimation/tst_qpropertyanimation.cpp
+++ b/tests/auto/qpropertyanimation/tst_qpropertyanimation.cpp
@@ -95,6 +95,7 @@ private slots:
     void zeroDurationStart();
     void operationsInStates_data();
     void operationsInStates();
+    void oneKeyValue();
 };
 
 tst_QPropertyAnimation::tst_QPropertyAnimation()
@@ -850,5 +851,35 @@ void tst_QPropertyAnimation::operationsInStates()
 #undef Resume
 #undef Stop
 
+void tst_QPropertyAnimation::oneKeyValue()
+{
+    QObject o;
+    o.setProperty("ole", 42);
+    QCOMPARE(o.property("ole").toInt(), 42);
+
+    QPropertyAnimation animation(&o, "ole");
+    animation.setStartValue(43);
+    animation.setEndValue(44);
+    animation.setDuration(100);
+
+    animation.setCurrentTime(0);
+
+    QVERIFY(animation.currentValue().isValid());
+    QCOMPARE(animation.currentValue().toInt(), 43);
+    QCOMPARE(o.property("ole").toInt(), 42);
+
+    // remove the last key value
+    animation.setKeyValueAt(1.0, QVariant());
+
+    // we will neither interpolate, nor update the current value
+    // since there is only one 1 key value defined
+    animation.setCurrentTime(100);
+
+    // the animation should not have been modified
+    QVERIFY(animation.currentValue().isValid());
+    QCOMPARE(animation.currentValue().toInt(), 43);
+    QCOMPARE(o.property("ole").toInt(), 42);
+}
+
 QTEST_MAIN(tst_QPropertyAnimation)
 #include "tst_qpropertyanimation.moc"