Fix bug where form/fieldset :valid/:invalid won't be recalculated upon control's willValidate change

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 59 matching lines @@
 #endif
     , m_associatedElementsAreDirty(false)
     , m_imageElementsAreDirty(false)
     , m_hasElementsAssociatedByParser(false)
     , m_didFinishParsingChildren(false)
     , m_wasUserSubmitted(false)
     , m_isSubmittingOrInUserJSSubmitEvent(false)
     , m_shouldSubmit(false)
     , m_isInResetFunction(false)
     , m_wasDemoted(false)
+    , m_invalidControlsCount(0)
     , m_pendingAutocompleteEventsQueue(GenericEventQueue::create(this))
 {
 }
 
 PassRefPtrWillBeRawPtr<HTMLFormElement> HTMLFormElement::create(Document& document)
 {
     UseCounter::count(document, UseCounter::FormElement);
     return adoptRefWillBeNoop(new HTMLFormElement(document));
 }
 
@@ skipping 619 matching lines @@
         if (!elements[i]->isFormControlElement())
             continue;
         HTMLFormControlElement* control = toHTMLFormControlElement(elements[i]);
         if (control->isSuccessfulSubmitButton())
             return control;
     }
 
     return 0;
 }
 
-void HTMLFormElement::setNeedsValidityCheck()
+void HTMLFormElement::setNeedsValidityCheck(ValidityRecalcReason reason, bool isValid)
 {
-    // For now unconditionally order style recalculation, which triggers
-    // validity recalculation. In the near future, implement validity cache and
-    // recalculate style only if it changed.
-    setNeedsStyleRecalc(SubtreeStyleChange, StyleChangeReasonForTracing::createWithExtraData(StyleChangeReason::PseudoClass, StyleChangeExtraData::Invalid));
+    bool formWasInvalid = m_invalidControlsCount > 0;
+    switch (reason) {
+    case ElementRemoval:
+        if (!isValid)
+            --m_invalidControlsCount;
+        break;
+    case ElementAddition:
+        if (!isValid)
+            ++m_invalidControlsCount;
+        break;
+    case ElementModification:
+        if (isValid)
+            --m_invalidControlsCount;
+        else
+            ++m_invalidControlsCount;
+        break;
+    }
+    if (formWasInvalid != (m_invalidControlsCount > 0))
+        setNeedsStyleRecalc(SubtreeStyleChange, StyleChangeReasonForTracing::createWithExtraData(StyleChangeReason::PseudoClass, StyleChangeExtraData::Invalid));
 }
 
 bool HTMLFormElement::checkValidity()
 {
     return !checkInvalidControlsAndCollectUnhandled(0, CheckValidityDispatchInvalidEvent);
 }
 
 bool HTMLFormElement::checkInvalidControlsAndCollectUnhandled(WillBeHeapVector<RefPtrWillBeMember<HTMLFormControlElement> >* unhandledInvalidControls, CheckValidityEventBehavior eventBehavior)
 {
+    if (!unhandledInvalidControls && eventBehavior == CheckValidityDispatchNoEvent)
+        return m_invalidControlsCount;
+
     RefPtrWillBeRawPtr<HTMLFormElement> protector(this);
     // Copy associatedElements because event handlers called from
     // HTMLFormControlElement::checkValidity() might change associatedElements.
     const FormAssociatedElement::List& associatedElements = this->associatedElements();
     WillBeHeapVector<RefPtrWillBeMember<FormAssociatedElement> > elements;
     elements.reserveCapacity(associatedElements.size());
     for (unsigned i = 0; i < associatedElements.size(); ++i)
         elements.append(associatedElements[i]);
-    bool hasInvalidControls = false;
+    int invalidControlsCount = 0;
     for (unsigned i = 0; i < elements.size(); ++i) {
         if (elements[i]->form() == this && elements[i]->isFormControlElement()) {
             HTMLFormControlElement* control = toHTMLFormControlElement(elements[i].get());
             if (!control->checkValidity(unhandledInvalidControls, eventBehavior) && control->formOwner() == this)
-                hasInvalidControls = true;
+                ++invalidControlsCount;
         }
     }
-    return hasInvalidControls;
+    if (eventBehavior == CheckValidityDispatchNoEvent)
+        ASSERT(invalidControlsCount == m_invalidControlsCount);
+    return invalidControlsCount;
 }
 
 bool HTMLFormElement::reportValidity()
 {
     return validateInteractively();
 }
 
 Element* HTMLFormElement::elementFromPastNamesMap(const AtomicString& pastName)
 {
     if (pastName.isEmpty() || !m_pastNamesMap)
@@ skipping 96 matching lines @@
 }
 
 void HTMLFormElement::setDemoted(bool demoted)
 {
     if (demoted)
         UseCounter::count(document(), UseCounter::DemotedFormElement);
     m_wasDemoted = demoted;
 }
 
 } // namespace