Bug 115708 – select element’s default selection is affected by CSS rules

• Status: NEW
• Component: Forms

[Ryosuke Niwa]

We should consider merging
https://chromium.googlesource.com/chromium/blink/+/938d5b4ad28b364346bc8c182b4a71b13d20975d

<select> default selection is affected by CSS styling.

If we have option:checked selectors, HTMLOptionElement::selected is called even
when its owner option list is incomplete. It makes the default selection
incorrect. To avoid this issue, we introduce isParsingInProgress flag, and
HTMLOptionElement::selected doesn't call
HTMLSelectELement::updateListItemSelectedStates if the flag is true.

Because this patch reduces the number of calls to
RenderMenuList::updateFromElement, a bug of RenderText is unveiled. A change of
RenderMenuList::setText avoids the bug.

Also, this change and accessibility/add-to-menu-list-crashes.html test unveiled a
bug that HTMLSelectElement::selectedOption didn't update selection status.

Tests:
* fast/forms/select/menulist-disabled-option.html is udpated. This patch updates
  some option text so that expectations are easy to understand.
* fast/forms/HTMLOptinElement_selected3.html:
  Update description, and make this work on IE10.
  The new behavior is compatible with IE10.

[Ahmad Saleem]

I changed the test cases from Chromium Patch:

JSFiddle - menulist-disabled-option.html - https://jsfiddle.net/825ab7jp/show

Safari 15.6.1 still fail last one while all other browsers (Chrome Canary 106 and Firefox Nightly 105) pass all tests.

In other test - HTMLOptionElement_selected3 - https://jsfiddle.net/oLrs30tk/show

Both Safari 15.6 and Chrome Canary 106 show "O" ([theSelect].selectedIndex = 0), while Firefox Nightly 105 show "-1".

[Ahmad Saleem]

(In reply to Ahmad Saleem from comment #1)
> I changed the test cases from Chromium Patch:
> 
> JSFiddle - menulist-disabled-option.html - https://jsfiddle.net/825ab7jp/show
> 
> Safari 15.6.1 still fail last one while all other browsers (Chrome Canary
> 106 and Firefox Nightly 105) pass all tests.
> 
> In other test - HTMLOptionElement_selected3 -
> https://jsfiddle.net/oLrs30tk/show
> 
> Both Safari 15.6 and Chrome Canary 106 show "O" ([theSelect].selectedIndex =
> 0), while Firefox Nightly 105 show "-1".

Safari 16.5 passes both and matches with Chrome Canary 115.

Firefox Nightly 115 is still different in this - https://jsfiddle.net/oLrs30tk/show

Can we close this now? Or we need to still get this patch in?