Greasy Fork

Doesn't work properly on https://www.oreilly.com/member/login/?next=%2Fapi%2Fv1%2Fauth%2Fopenid%2Fauthorize%2F%3Fclient_id%3D235442%26redirect_uri%3Dhttps%3A%2F%2Flearning.oreilly.com%2Fcomplete%2Funified%2F%26state%3Ddu2eDaApgma4MWM9bIUTrfLWPNfJmMro%26response_type%3Dcode%26scope%3Dopenid%2Bprofile%2Bemail&locale=en

I don't care about this website anyways.

This means that the script most likely also doesn't work on websites that "requires" the user to manually write the username/password inputs

I added what you describe as a limitation in the script description.

Thanks,well that also "works"...

But everyone would enjoy your script more if you could find a "universal" way to populate these fields.

A workaround for such sites, which have their own various event listeners (onFocus, onBlur, onChange) on the user/pass fields -which get in the way-, is to temporarily disable JavaScript on the site (via e.g. uBlock Origin or NoScript extensions) and reload the page.

That's interesting, I think that this would just break the website and the login, but you can try using these codes I'm using to "disable js" on any page

Function.prototype.apply = function() {}; /*Function.prototype.bind = function(){};*/ //Disable JS on the website

You can add an option on the menu when the user clicks on the login box, the user can try to normally use your script, but if doesn't work then the user could use this option to call the functions I shared, then reload the website and the user will see if the script will work this time or not

I mentioned that method merely as a last resort for the user to try. I'm sure that many/many of the times it won't help (it breaks the login on your oreilly.com link !).

I don't won't to add such function to the script first and topmost because you can't disable JavaScript with a JavaScript script.
(with a userscript, you can't make sure your JS is the first to execute, nor can you reliably disable scripts all over the page.)
Using uBlock Origin or NoScript to (temp./perman.) disable all JavaScript (inline+third party) in the page, is already the best and most convenient working way to do (others are via chrome://settings/content/javascript and the browser DevTools) Also, even I wanted to add it, it would make the script deviate from its original structure.
Keep in mind that this userscript is an improved version of another one dated from 2009
which in turn was based on code even older one (2005) posted in oreilly.com !