Infinite Scroll Genesis inside div with overflow:scroll

functions.php

<?php
#  infinite scroll Genesis
remove_action( 'genesis_after_endwhile', 'genesis_posts_nav' );

function is_blog ()
{
	global  $post;
	$posttype = get_post_type($post );
	return ( ((is_archive()) || (is_author()) || (is_category()) || (is_home()) || (is_single()) || (is_tag())) && ( $posttype == 'post')  ) ? true : false ;
}


/*
 * Add a CSS ID to main element
 * @param  array $attributes Existing attributes.
  * @return array Amended attributes.
*/
function gn_attributes_content( $attributes )
{
	if( is_blog() )
	{
		$attributes['id'] = 'i-scroll';
	}
	return $attributes;
}
add_filter( 'genesis_attr_content', 'gn_attributes_content' );



function gn_script_i_scroll()
{
	if( is_blog() )
	{
		wp_register_script( 'i-scroll', get_stylesheet_directory_uri() .'/js/infinite-scroll.js', array('jquery'), '1.0', true );
		wp_enqueue_script( 'i-scroll' );
	}
}
add_action('wp_enqueue_scripts','gn_script_i_scroll');


add_action('genesis_after_loop','gn_loader');
function gn_loader()
{
	?>
	<p class="chargement-billet loader" style="display: none"><img class="loader-img" src="<?php echo get_stylesheet_directory_uri(); ?>/images/ajax-loader.gif"></p>
<?php
}

infinite-scroll.js

/**
 * Infinite Scroll - Genesis
 * Thierry Pigot
 * 20150722
 */

jQuery(document).ready(function($)
{
    var loader = $('.loader'),
        busy = false,
        i = 1;

    $('.content-sidebar-wrap').scroll(function () {
        var $this = $(this);
        var height = this.scrollHeight - $this.height(); // Get the height of the div
        var scroll = $this.scrollTop(); // Get the vertical scroll position

        //var lastArticle = $('#i-scroll article:last').height();

        var isScrolledToEnd = ( scroll >= height );
        //var isScrolledToEnd = ( scroll >= ( height - ( lastArticle/3) ) );

        if (isScrolledToEnd)
        {
            // incrémente le numéro de page
            i++;

            // on est occupé
            busy = true;

            // afficher le loader
            loader.show();

            $.get(document.location.href + 'page/' + i )
                .done( function( data )
                {
                    // masque le loader
                    loader.hide();

                    // ajouter les nouveau article
                    $('#i-scroll article:last').after( $('#i-scroll', data).html() );

                    // on met jour la valeur offset du dernier article
                    height = $('#i-scroll article:last').offset();

                    // met à jour busy
                    busy = false;
                })
                .fail( function()
                {
                    // on masque le loader
                    loader.hide();
                }
            );
        }
    });
});