<button> shouldn't have activation behavior when it is not in a form

[smaug----]

data:text/html,<a href="data:text/html,link followed"><button>click me</button></a> follows the link in Gecko and Blink.

Spec says in https://html.spec.whatwg.org/multipage/interaction.html#nearest-activatable-element
"If target has a defined activation behaviour, then return target and abort these steps."

And button has activation behavior
https://html.spec.whatwg.org/multipage/forms.html#the-button-element:activation-behaviour
Even for state Button it has it, even though the activation behavior is to do nothing.

[smaug----]

Looks like data:text/html,<a href="data:text/html,link followed"><form><button type=button>click me</button></form></a> follows the link too. So type=button shouldn't ever have action behavior defined, and type=submit and type=reset depend on whether the button is in form.

Don't know about type=menu. Does any engine even support it?

[domenic]

type=menu is tracked in #237.

Buttons in the button state already have an activation behavior of "Do nothing". Is the bug report here to be more explicit that "Do nothing" means "has no activation behavior" and thus fails to trigger the "If target has a defined activation behavior" clause?

[smaug----]

It is hard to parse "Do nothing" as "does not have activation behavior" (since I can imagine cases when there is some valid activation behavior and it could be 'do nothing').
So yes, type=button always and if my testing is right type=submit and type=reset when they aren't in a form should not have activation behavior at all.

[domenic]

That makes sense. I am just imagining the intent was for it to be "does not have activation behavior" since that gives reasonable results, but it definitely could be clearer about this.

[smaug----]

#1568 is related issue.

[zcorpan]

Testing with

data:text/html,<a href="javascript:alert('link followed');"><form onsubmit="alert('form submitted'); return false;"><button type=button onclick="this.type = 'submit';">click me</button></form></a>

now the form is submitted in Safari/Chrome/Firefox.

But without a form the link is followed:

data:text/html,<a href="javascript:alert('link followed');"><button type=button onclick="this.type = 'submit';">click me</button></a>

[annevk]

I would suggest we fix this as follows:

• Make "activation behavior" and its legacy counterparts null by default.
• Add "has activation behavior" which is an algorithm that returns true when "activation behavior" is non-null and can be overridden with a custom implementation.
• Make everything that is conditional upon activation behavior use "has activation behavior" as the condition.
• Give "button" its own "has activation behavior" algorithm that takes form into account. "input" might need one too?