in salesforce/canvas/public/javascripts/canvas-all.js [805:821]
function loginUrl() {
var i,
nvs,
nv,
q = self.location.search;
if (q) {
q = q.substring(1);
nvs = q.split('&');
for (i = 0; i < nvs.length; i += 1) {
nv = nvs[i].split('=');
if ('loginUrl' === nv[0]) {
return decodeURIComponent(nv[1]) + '/services/oauth2/authorize';
}
}
}
return 'https://login.salesforce.com/services/oauth2/authorize';
}