jQuery animate += and latest version

Question

Each time I click the div "blue" it moves 100px. It worked well and one day I realize it stopped working. After trying a lot of things I discovered that the problem is with the latest version of jQuery 1.10 Now it just moves 100px once. It is as it ignores the += . I could not find if it is deprecated? If so, what is the right way to do that now?

You could see it working here:http://jsfiddle.net/RB4eJ/1/
(This is working in jQuery 1.9.1. But it is not in 1.10)

$(function(){
    $(".blue").click(function() {
        $(".blue").animate({left: "+=100"}, 500)    
    });
})

Answer 1

If it is a bug I hope they fix it because it was useful. However for now you can do something like this:

$(".blue").click(function() {
    var new_left = +$(this).css("left").replace("px", "") + 100;
    $(".blue").animate({left: new_left + "px"}, 500)    
});

Or as @adeneo suggested:

$(".blue").click(function() {
    $(this).animate({left: $(this).position().left+100}, 500);  
});

See working demo with jQuery 2.x

Performance test