Fixes #7213 Collapse plugin does not correctly set the "collapsed" class on accordion heading links

js/bootstrap-collapse.js

@@ -160,6 +160,12 @@
         || e.preventDefault()
         || (href = $this.attr('href')) && href.replace(/.*(?=#[^\s]+$)/, '') //strip for ie7
       , option = $(target).data('collapse') ? 'toggle' : $this.data()
+      , parent = $this.attr('data-parent')
+      , $parent = parent && $(parent)
+
+    if ($parent) {
+      $parent.find('[data-toggle=collapse][data-parent=' + parent + ']').not($this).addClass('collapsed')
+    }
     $this[$(target).hasClass('in') ? 'addClass' : 'removeClass']('collapsed')
     $(target).collapse(option)
   })