password_fill does not work for elastic/kibana login form

[twouters]

Version info:
qutebrowser v1.11.1
Git commit:
Backend: QtWebEngine (Chromium 77.0.3865.129)
Qt: 5.14.2

Does the bug happen if you start with --temp-basedir?:
yes

Description
password_fill userscript does not fill username and password on elastic login form.
I'm not aware of a public server where this can be validated, but it looks sort of reproducible on their demo setup.

How to reproduce
Create a password store entry for demo.elastic.co with pass:

demo
username: demo

Head over to the account settings page for the demo user (https://demo.elastic.co/app/kibana#/account?_g=()) and run password_fill userscript to fill the password fields (like it does for most supported websites as far as I'm aware) and notice that the password fields remain empty.

[The-Compiler]

Sorry, this got lost in my inbox. I don't use that userscript myself, but maybe someone who contributed to it in the past knows more? Taking the freedom to ping @t-wissmann @kepi, @paretje and @sarg who worked on the JavaScript part of the script in the past.

[t-wissmann]

The reason that this does not work is that on this password-reset-page, there is no html <form>. There are <input ..> fields, but they are not connected by a surrounding <form> tag. It is quite hacky already to put in the credentials into every form having a password input, I think it would be too hacky/risky to put in the username and password into every input field.