Commented Issue: Phone Toolkit: MultiSelectList throws ArgumentOutOfRangeException if IsSelectionEnabled is true on page navigation return [9744]

In case you're wondering, I'm running changeset 70828 so not quite the August toolkit.

I ran into this issue because I have an AppBar button bound to just toggle IsSelectionEnabled. If you tap the button, leave the multiselectlist in the "select items but nothing is selected" state, navigate away from the page, then come back you get a lovely exception with the following exception message/stacktrace:

Specified argument was out of the range of valid values.
Parameter name: childIndex
at System.Windows.Media.VisualTreeHelper.GetChild(DependencyObject reference, Int32 childIndex)
at Microsoft.Phone.Controls.ItemsControlExtensions.GetItemsInViewPort(ItemsControl list)
at Microsoft.Phone.Controls.MultiselectList.OpenSelection()
at Microsoft.Phone.Controls.MultiselectList.OnIsSelectionEnabledPropertyChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e)
at System.Windows.DependencyObject.RaisePropertyChangeNotifications(DependencyProperty dp, Object oldValue, Object newValue)
at System.Windows.DependencyObject.UpdateEffectiveValue(DependencyProperty property, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, ValueOperation operation)
at System.Windows.DependencyObject.RefreshExpression(DependencyProperty dp)
at System.Windows.Data.BindingExpression.RefreshExpression()
at System.Windows.Data.BindingExpression.SendDataToTarget()
at System.Windows.Data.BindingExpression.SourceAcquired()
at System.Windows.Data.BindingExpression.System.Windows.IDataContextChangedListener.OnDataContextChanged(Object sender, DataContextChangedEventArgs e)
at System.Windows.Data.BindingExpression.DataContextChanged(Object sender, DataContextChangedEventArgs e)
at System.Windows.FrameworkElement.OnDataContextChanged(DataContextChangedEventArgs e)
at System.Windows.FrameworkElement.OnAncestorDataContextChanged(DataContextChangedEventArgs e)
at System.Windows.FrameworkElement.NotifyDataContextChanged(DataContextChangedEventArgs e)
at System.Windows.FrameworkElement.OnAncestorDataContextChanged(DataContextChangedEventArgs e)
at System.Windows.FrameworkElement.NotifyDataContextChanged(DataContextChangedEventArgs e)
at System.Windows.FrameworkElement.OnAncestorDataContextChanged(DataContextChangedEventArgs e)
at System.Windows.FrameworkElement.NotifyDataContextChanged(DataContextChangedEventArgs e)
at System.Windows.FrameworkElement.OnTreeParentUpdated(DependencyObject newParent, Boolean bIsNewParentAlive)
at System.Windows.DependencyObject.UpdateTreeParent(IManagedPeer oldParent, IManagedPeer newParent, Boolean bIsNewParentAlive, Boolean keepReferenceToParent)
at MS.Internal.FrameworkCallbacks.ManagedPeerTreeUpdate(IntPtr oldParentElement, IntPtr parentElement, IntPtr childElement, Byte bIsParentAlive, Byte bKeepReferenceToParent, Byte bCanCreateParent)
at MS.Internal.XcpImports.MeasureOverrideNative(IntPtr element, Single inWidth, Single inHeight, Single& outWidth, Single& outHeight)
at MS.Internal.XcpImports.FrameworkElement_MeasureOverride(FrameworkElement element, Size availableSize)
at System.Windows.FrameworkElement.MeasureOverride(Size availableSize)
at Microsoft.Phone.Controls.PhoneApplicationFrame.MeasureOverride(Size availableSize)
at System.Windows.FrameworkElement.MeasureOverride(IntPtr nativeTarget, Double inWidth, Double inHeight, Double& outWidth, Double& outHeight)


Workaround: in your OnNavigatedFrom event in either the page code-behind or your ViewModel in my case, set IsSelectionEnabled = false. A bound VM properly fires the property change so that the next time you come back the control is in the proper default state.

You could say this is an extension of the certification requirement to unselect any item used for navigation in a list. I don't mind this workaround as it's rather minor but I suspect the control can probably handle that exception for us.
Comments: Fixed on changeset 79718