HTML :enable and :disabled are not quite conformant

[SimonSapin]

These should match :enabled, but currently do not:

li elements that are children of menu elements, and that have a child element that defines a command, if the first such element's Disabled State facet is false (not disabled)

(Similarly for :disabled with Disabled State facet is true (disabled))

Form elements should be considered disabled

... if its disabled attribute is set, or if it is a descendant of a fieldset element whose disabled attribute is set and is not a descendant of that fieldset element's first legend element child, if any.

The last part was skipped, so the current implementation is:

... if its disabled attribute is set, or if it is a descendant of a fieldset element whose disabled attribute is set

[Gallaecio]

Those links are currently broken. They are available in the wayback machine, though:

• https://web.archive.org/web/20120326121916/http://www.w3.org/TR/html5/links.html#selector-enabled
• https://web.archive.org/web/20120404110115/http://www.w3.org/TR/html5/attributes-common-to-form-controls.html#concept-fe-disabled

None of the specifications linked from the Mozilla documentation mention these cases.

Moreover, the two linked specifications which do detail what should be considered :enabled or :disabled, which are the HTML5 specification and the HTML Living Standard, seem to provide a definition that is simpler than our current implementation.

@redapple, @kmike, @dangra What should we do? Should we follow the living standard? Should we follow the HTML5 standard? Should we make it possible to select which standard to follow?

[blaise-io]

I just ran into an issue related to this.

I was expecting <input type="hidden"> to match input:enabled, but it didn't match because of

cssselect/cssselect/xpath.py

Line 755 in cb7a7e2

(name(.) = 'input' and @type != 'hidden') or

cssselect's implementation does not match the spec and it also does not match the implementation in Chrome and Firefox where input:enabled does match the hidden input element.