Nested TrimEmptyGroupingNodesVisibilityProvider

[Kaneraz]

When nesting TrimEmptyGroupingNodesVisibilityProvider it fails to trim the parent node.

<mvcSiteMapNode title="Catalog" visibilityProvider="MvcSiteMapProvider.TrimEmptyGroupingNodesVisibilityProvider, MvcSiteMapProvider" clickable="false">
    <mvcSiteMapNode title="Parts" visibilityProvider="MvcSiteMapProvider.TrimEmptyGroupingNodesVisibilityProvider, MvcSiteMapProvider" clickable="false" >
        <mvcSiteMapNode title="Search"  area="Materials" controller="Parts" action="Search" />
        <mvcSiteMapNode title="Add"  area="Materials" controller="Parts" action="Add" />
    </mvcSiteMapNode>
    <mvcSiteMapNode title="Assets"  area="Materials" controller="Asset" action="Search" />
</mvcSiteMapNode>

When it gets to the parent node the 2nd one is just hidden not trimmed so it has child nodes.

[Kaneraz]

I rolled my own visibility provider to fix it and overrode IsVisible as follows:

public override bool IsVisible(ISiteMapNode node, IDictionary<string, object> sourceMetadata)
        {
            var childNodes = node.ChildNodes;
            return childNodes == null || childNodes.Any(c => c.IsVisible(sourceMetadata)) || node.Clickable;
        }

I'll see if I can get set up to push a patch for it and add some tests to update the built in provider.