This is related to this gist https://gist.github.com/itzikbenh/5cc5fb05b393a1516af70bc0fde3fa18 I'm experimenting with solutions to back button. Not ready yet

infinite-scroll.js

(function($) {
    //Handles the infinite-scroll part and adds new content to sessionStorage so we can return user to the same position
    //when he hits the back button
    $(window).scroll(function() {
        var url = $('.nav-links .next').attr('href');
        if (url && $(window).scrollTop() > $(document).height() - $(window).height() - 150) {
            //To avoid repeating calls we set the paginate container to hold only text and we remove the links.
            //that way url variable would be empty, thus if statement would return false and not continure to the get call.
            $('.navigation').text("Fetching more posts..."); //You can optionally load an icon-loader or something.
            $(".loader").removeClass("hidden"); //Show the loader icon

            $.get(url, function(data) {
                var dom        = $(data);
                var next_posts = dom.find('.posts-container').html();
                var pagination = dom.find('.navigation').html();
                $('.posts-container').append(next_posts);
                $('.navigation').html(pagination); //We want to load the new pagination with new links.
                $(".loader").addClass("hidden"); //Hide the loader icon

                //We want to check if we have any post content in session storage.
                //If we don't we will set it to empty string just incase an append to it the new data.
                var posts_to_append = sessionStorage.getItem("posts_to_append");
                if(!posts_to_append) {
                    posts_to_append = "";
                }
                sessionStorage.setItem("posts_to_append", posts_to_append + next_posts);
                //Here we always need the newest pagination avaiable so we replace instead of appending.
                sessionStorage.setItem("pagination_to_append", pagination);
            });
        }
    });
    
    //Handles returning the user to his previous position with the previous loaded content. Also makes sure to reset
    //everything on page refresh while user is the posts page. 
    $(document).ready(function() {
        //Some browsers are using caching so we really don't need to remember the user's location. They will do it for us.
        //From what I checked it seems the Safari and Firefox are using cache to return the user to his previous location
        //when he hits the back button. This is what I'm only doing it manually for Chrome now. Not tested yet in
        //IE or Opera.

        //Code snippet I found on stackoverflow that detects the user's browser. 
        // Opera 8.0+
        var isOpera = (!!window.opr && !!opr.addons) || !!window.opera || navigator.userAgent.indexOf(' OPR/') >= 0;
        // Firefox 1.0+
        var isFirefox = typeof InstallTrigger !== 'undefined';
        // At least Safari 3+: "[object HTMLElementConstructor]"
        var isSafari = Object.prototype.toString.call(window.HTMLElement).indexOf('Constructor') > 0;
        // Internet Explorer 6-11
        var isIE = /*@cc_on!@*/false || !!document.documentMode;
        // Edge 20+
        var isEdge = !isIE && !!window.StyleMedia;
        // Chrome 1+
        var isChrome = !!window.chrome && !!window.chrome.webstore;

        if(isChrome) {

            //We use to identify when user clicks the refresh icon.
            window.onbeforeunload = unloadPage();
            function unloadPage() {
                var clicked_post_link = sessionStorage.getItem("clicked_post_link");

                if(clicked_post_link === "no" || !clicked_post_link) {
                    sessionStorage.removeItem("posts_to_append");
                    sessionStorage.removeItem("pagination_to_append");
                    window.scrollTo(0, 0);
                }
            }

            $(document).on( "click", "a", function(e) {
                e.preventDefault();
                console.log("clicked link");
                //If user doesn't click on a post link we will reset storage to its default.
                if($(this).hasClass('post-page')) {
                    sessionStorage.setItem("scroll_position", $(window).scrollTop());
                    sessionStorage.setItem("clicked_post_link", "yes");
                    window.location = $(this).attr('href');
                } else {
                    sessionStorage.removeItem("posts_to_append");
                    sessionStorage.removeItem("pagination_to_append");
                    sessionStorage.setItem("clicked_post_link", "no");
                    window.location = $(this).attr('href');
                }
            });

            var scroll_position = sessionStorage.getItem("scroll_position");
            var content         = sessionStorage.getItem("posts_to_append");
            var pagination      = sessionStorage.getItem("pagination_to_append");

            if(content) {
                $('.posts-container').append(content);
                $('.navigation').html(pagination);
                window.scrollTo(0, scroll_position);
                //We want to reset it so if user click page refresh it will reset the session.
                sessionStorage.setItem("clicked_post_link", "no");
            }

        }
    });
})(jQuery);