$getElement returns wrong results when there is no $refresh method

[divdavem]

Plunk

Here is the plunk to reproduce the issue:
http://embed.plnkr.co/arLGKhwphORMRl9gmh1O

Click on the button.

Expected behavior: an alert is displayed with the following content:
On click: this.$getElement(0) = BUTTON

Actual behavior: the content of the alert is wrong:
On click: this.$getElement(0) = H1

HSP file

var klass = require("hsp/klass");
var Ctrl = klass({
  // Uncomment the following line and the $getElement method will work fine:
  // $refresh: function () {},
  click: function () {
    var expectedButton = this.$getElement(0);
    alert("On click: this.$getElement(0) = " + expectedButton.tagName);
  }
});
# template myCpt using c:Ctrl
  <button onclick="{c.click()}">Click me</button>
# /template
# template main
  <h1>Title</h1>
  <#myCpt />
# /template
main().render("output"); 

Note

$getElement returns a correct value if there is a $refresh method in the controller.
This seems to be linked to the needCommentNodes variable in cptcomponent.js:

var needCommentNodes=(this.createPathObservers() || this.ctlConstuctor.$refresh);

It is confusing to have a method which can return wrong values. If we do not want to always include comment nodes, it would be better to remove the $getElement method and to pass elements as parameters to $refresh, as discussed here

Hashspace version

Tested with version 4491708.

[benouat]

I already discussed that with @b-laporte , and apparently his initial plan was to only authorized the usage of $getElement() when you have a $refresh() implementation.
I was also thinking about dynamically adding that $getElement()method only when you define a $refresh() one.

For the solution regarding arguments, it can simply not be done like that. 😞 Just think about customisation, if you override a template, but keep the same controller, then your arguments might be different according to the changed template, and then you root element is different.