Hide orphaned elements - the last unfull row of a grid, call on parent with child selector

gistfile1.js

//Ignore if you already have it:
$.fn.reverse = [].reverse;

//Hide orphaned thumbs, call on parent with child selector
$.fn.hideOrphans = function(selector, totalCountSelector){
  var selector = selector;
  $(this).each(function(){
    var $children = $(this).find(selector);
    $children.filter('.hidden-orphan').show().removeClass('hidden-orphan');
    if($(this).hasClass('show-orphans')) {
      return true;
    }
    var lastRow = [];
    var secondToLastRow = [];
    var lastRowOffset = Math.floor($children.last().position().top);
    var secondToLastRowOffset = -1;
    $children.reverse().each(function(){
      var top = Math.floor($(this).position().top);
      if(top == lastRowOffset) {
        //Build last row
        lastRow.push(this);
      } else {
        //Build second to last row
        if(secondToLastRowOffset == -1) {
          secondToLastRowOffset = top;
        }
        if(top == secondToLastRowOffset) {
          secondToLastRow.push(this);
        } else {
          //Finally added last two rows
          return false;
        }
      }
    });
    //Any orphans to hide?
    var hidden = 0;
    if(secondToLastRow.length != 0 && secondToLastRow.length != lastRow.length) {
      $(lastRow).addClass('hidden-orphan').hide();
      hidden = lastRow.length;
    }
    if(totalCountSelector) {
      var t = $children.length - hidden;
      $(this).find(totalCountSelector).html(t);
    }
  });
  return $(this);
};

 //Sample usage
 $(window).on('debouncedresize hideorphans', function(){
   $('.product-list').hideOrphans('.product-block:not(.placeholder)', '.show-more .current-count');
 }).trigger('hideorphans');