Uplift this to HTML/CSSOM

[annevk]

How do you feel about trying to standardize this? See whatwg/html#2464 for some prior discussion around this functionality.

Also, great work documenting the status quo!

[arai-a]

yeah, it would be nice if we can standardize this, and hopefully make the behavior consistent across browsers,
that will help web-devs.
if we standardize, we should look into the behavior of mobile browsers etc as well tho.

about the IsPopup condition, Firefox's behavior can be modified.
the current behavior is based on the mix of others and previous behavior about when to open new window,
and, for example, changing it to just using width would also work.

[arai-a]

Looks like https://html.spec.whatwg.org/multipage/browsers.html#the-rules-for-choosing-a-browsing-context-given-a-browsing-context-name is the right place to modify,
given that it's talking about popup blocker.

[annevk]

Yeah, though note that what HTML calls a popup is all things that open in a new tab/window, not just windows with a popup look-and-feel.

[arai-a]

okay, if there's no distinction between window/tab/popup in https://html.spec.whatwg.org/multipage/browsers.html#the-rules-for-choosing-a-browsing-context-given-a-browsing-context-name ,
we can keep using "window open steps" as the modification target,
after https://bugzilla.mozilla.org/show_bug.cgi?id=1661643 gets fixed (that removes "current tab" case).