Foldable-nav fix (google#1070)

layouts/partials/sidebar-tree.html

@@ -42,7 +42,7 @@
 {{ $ulNr := .ulNr -}}
 {{ $ulShow := .ulShow -}}
 {{ $active := and (not $shouldDelayActive) (eq $s $p) -}}
-{{ $activePath := and (not $shouldDelayActive) ($p.IsDescendant $s) -}}
+{{ $activePath := and (not $shouldDelayActive) (or (eq $p $s) ($p.IsDescendant $s)) -}}
 {{ $show := cond (or (lt $ulNr $ulShow) $activePath (and (not $shouldDelayActive) (eq $s.Parent $p.Parent)) (and (not $shouldDelayActive) (eq $s.Parent $p)) (not $p.Site.Params.ui.sidebar_menu_compact) (and (not $shouldDelayActive) ($p.IsDescendant $s.Parent))) true false -}}
 {{ $mid := printf "m-%s" ($s.RelPermalink | anchorize) -}}
 {{ $pages_tmp := where (union $s.Pages $s.Sections).ByWeight ".Params.toc_hide" "!=" true -}}