forcetk.Client constructor builds incorrect instanceUrl when running on na1.salesforce.com

Current code fails to take into account VF hosts such as na1.salesforce.com:

    // location.hostname is of the form 'abc.na1.visual.force.com', so we
    // can simply split it on '.' and take the second element of the
    // resulting array
    this.instance_url = "https://" + location.hostname.split(".")[1]
    + ".salesforce.com";

As a result, it erroneously builds an instanceUrl such as salesforce.salesforce.com. Since there is no way to directly get the instance component or the whole URL in Visualforce, an acceptable heuristic would be to look at the number of elements in the hostname and choose the first or second as appropriate:

    // location.hostname can be of the form 'abc.na1.visual.force.com' or
    // 'na1.salesforce.com'. Split on '.', and take the [1] or [0] element
    // as appropriate
    var elements = location.hostname.split(".");
    var instance = (elements.length == 3) ? elements[0] : elements[1];
    this.instance_url = "https://"+instance+".salesforce.com";

Many thanks to @jeffdonthemic for the bug report!

Look at structure of VF hostname and choose first or second element for instance as appropriate. Closed by 785dc35.

[jeffdonthemic]

Pat, just tested this patch and it works great! Go ahead and close and have a lovely day!