Function call freezes browser when debugging

Here’s the short version of the script that causing this issue:

array = this.shuffle(array);

RandomImage.prototype.shuffle = function(ar)
    var currIndex = ar.length, tempValue, randIndex;
    while(0 !== currIndex)
        randIndex = Math.floor(Math.random() * currIndex);
        currIndex -= 1;
        tempValue = ar[currIndex];
        ar[currIndex] = ar[randIndex];
        ar[randIndex] = tempValue;
    return ar;

When I put a break point on array = this.shuffle(array); and try to step into the function, any tabs I have open on the current browser window throw an error saying can’t open this page.

Link to project and script (RandomImage.js)