<fieldset> should be ignored in interactive validation

Source/core/html/HTMLFormElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 285 matching lines @@
         HTMLFormControlElement* unhandled = unhandledInvalidControls[i].get();
         if (unhandled->isFocusable()) {
             unhandled->showValidationMessage();
             break;
         }
     }
     // Warn about all of unfocusable controls.
     if (document().frame()) {
         for (unsigned i = 0; i < unhandledInvalidControls.size(); ++i) {
             HTMLFormControlElement* unhandled = unhandledInvalidControls[i].get();
-            if (unhandled->isFocusable())
+            if (unhandled->isFocusable() || unhandled->formControlType() == "fieldset")

[tkent, 2015/06/25 06:16:45]

Here is not the correct place to check if it's <fieldset>.

The specification says fieldset is omitted in "statically validate the
constraints" step.
https://html.spec.whatwg.org/multipage/forms.html#statically-validate-the-con...
In our implementation, it's
HTMLFormElement::checkInvalidControlsAndCollectUnhandled().
We should add isSubmittableElement [1] to HTMLFormControlElement, and
checkInvalidControlsAndCollectUnhandled() should be:

HTMLFormControlElement* control = toHTMLFormControlElement(elements[i].get());
if (control->isSubmittableElement() &&
!control->checkValidity(unhandledInvalidControls, eventBehavior) &&
control->formOwner() == this) {
    ++invalidControlsCount;

[1] https://html.spec.whatwg.org/multipage/forms.html#category-submit

                 continue;
             String message("An invalid form control with name='%name' is not focusable.");
             message.replace("%name", unhandled->name());
             document().addConsoleMessage(ConsoleMessage::create(RenderingMessageSource, ErrorMessageLevel, message));
         }
     }
     return false;
 }
 
 void HTMLFormElement::prepareForSubmission(Event* event)
@@ skipping 531 matching lines @@
 }
 
 void HTMLFormElement::setDemoted(bool demoted)
 {
     if (demoted)
         UseCounter::count(document(), UseCounter::DemotedFormElement);
     m_wasDemoted = demoted;
 }
 
 } // namespace