Posted by & filed under Developer Blog.

Whether you are using the old UsabilityInitiative extension, or the new split out Vector enhancements, you may have noticed an issue where the Collapsible Navigation functionality causes the first nav item in your list to remain open when the page loads. It doesn’t behave like the rest of the nav items that will remain in their closed or open state when you move to another page in your wiki. It simply remains open no matter what. If you wish to solve this little bug, you can replace line 3 of Vector.combined.min.js with the following:

$j('#mw-panel > div.portal').each(function(){if($j.cookie('vector-nav-'+$j(this).attr('id'))=='true'){$j(this).addClass('expanded').find('div.body').show();}else{$j(this).addClass('collapsed');}});
$j('#mw-panel > div.portal > h5').click(function(){$j.cookie('vector-nav-'+$j(this).parent().attr('id'),$j(this).parent().is('.collapsed'));
$j(this).parent().toggleClass('expanded').toggleClass('collapsed').find('div.body').slideToggle('fast');return false;});});
$j(document).ready(function(){if(!wgVectorEnabledModules.collapsibletabs){return true;}