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, 4 insertions, 2 deletions

diff --git a/src/corelib/animation/qpropertyanimation.cpp b/src/corelib/animation/qpropertyanimation.cpp
index adf3527..edcabaa 100644
--- a/src/corelib/animation/qpropertyanimation.cpp
+++ b/src/corelib/animation/qpropertyanimation.cpp
@@ -233,14 +233,16 @@ void QPropertyAnimation::updateState(QAbstractAnimation::State oldState,
         d->updateMetaProperty();
         QPropertyAnimation *oldAnim = hash->value(key, 0);
         if (oldAnim) {
-            //we try to stop the top level group
+            // try to stop the top level group
             QAbstractAnimation *current = oldAnim;
             while(current->group() && current->state() != Stopped) current = current->group();
             current->stop();
         }
         hash->insert(key, this);
         // Initialize start value
-        if (d->target && !d->defaultStartValue.isValid() && (d->atBeginning() || d->atEnd())) {
+        // ### review this line below, d->atEnd() ?
+        // ### avoid entering a state where start value is not set
+        if (d->target && (d->atBeginning() || d->atEnd())) {
             d->setDefaultStartValue(d->target->property(d->propertyName.constData()));
         }
     } else if (hash->value(key) == this) {