IE 11 - null model value makes form dirty

[razvangoga]

When binding a Summernote editor to a model with a Null value the ng-form in which the editor is placed becomes $dirty.
Sample here.

I could only duplicate this in IE 11 and Firefox Developer Edition v56.
In my PROD solution (a form with many more fields) i could also duplicate this in Edge and normal Firefox v57.
I could never duplicate this in Chrome.