When handlebars calls a function via a template, the context of the function call is always set to the data passed into the template. This botches functions that rely `this`.

handlebars-error.js

var handlebars = require('handlebars');
var tmpl = handlebars.compile('hello, {{person.getName}}');

var bob = Object.create({
  name: 'Bob'
, getName: function(){
    console.log( 'this', this );
    return this.name;
  }
});

// this { name: 'Bob' }
// 'Bob'
bob.getName()

// this { person: { name: 'Bob' } }
// 'hello, '
tmpl({ person: a })