Autofill works for forms with autocomplete="off"
From what I can grasp here: https://developer.mozilla.org/en-US/Firefox/Releases/30/Site_Compatibility#Security
If a field or form has autocomplete="off" set, the password manager should prompt the user to save the password, but the password can not be auto-filled into the field. This is not what I'm experiencing. I have a simple form with email and password field. Both the form itself and the fields have autocomplete="off", but Firefox 30 will still let me store the details and auto-fill them.
I cannot allow this, as it breaks Angular JS's binding causing things to not work.
Opaite Mbohovái (2)
You can try to set the signon.autofillForms pref to false on the about:config page.
Note that the signon.overrideAutocomplete pref controls the behavior with autocomplete=off
You can open the about:config page via the location/address bar and you can accept the warning and click "I'll be careful" to continue.
Ah, sorry. Yes that would solve the problem for me. But I'm building a website and need to fix it for all users.