HTMLInputElement::setValueForUser is used to autofill form elements. It differs from setting the form value normally because it creates a change event to trick websites into detecting user input. However, this is not enough for some websites that look only for input events and not change events to decide whether the user modified the form. On such websites, the user has to enter an extra character and then delete it as a workaround.

This fixes password autofill on https://my.cigna.com and https://myaccount.spireenergy.com. It has to be tested manually since this functionality is not exposed to JavaScript.