input[type=date] warns if specified string is invalid.

Source/core/html/HTMLInputElement.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, 2010, 2011 Apple Inc. All rights reserved.
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2007 Samuel Weinig (sam@webkit.org)
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2008 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2012 Samsung Electronics. All rights reserved.
@@ skipping 426 matching lines @@
     setNeedsWillValidateCheck();
 
     bool willStoreValue = m_inputType->storesValueSeparateFromAttribute();
 
     if (didStoreValue && !willStoreValue && hasDirtyValue()) {
         setAttribute(valueAttr, AtomicString(m_valueIfDirty));
         m_valueIfDirty = String();
     }
     if (!didStoreValue && willStoreValue) {
         AtomicString valueString = fastGetAttribute(valueAttr);
+        m_inputType->warnIfValueIsInvalid(valueString);
         m_valueIfDirty = sanitizeValue(valueString);
-    } else
+    } else {
+        m_inputType->warnIfValueIsInvalid(hasDirtyValue() ? m_valueIfDirty : fastGetAttribute(valueAttr).string());
         updateValueIfNeeded();
+    }
 
     m_needsToUpdateViewValue = true;
     m_inputTypeView->updateView();
 
     if (didRespectHeightAndWidth != m_inputType->shouldRespectHeightAndWidthAttributes()) {
         ASSERT(elementData());
         AttributeCollection attributes = attributesWithoutUpdate();
         if (const Attribute* height = attributes.find(heightAttr))
             attributeChanged(heightAttr, height->value());
         if (const Attribute* width = attributes.find(widthAttr))
@@ skipping 193 matching lines @@
         updateType();
     else if (name == valueAttr) {
         // We only need to setChanged if the form is looking at the default value right now.
         if (!hasDirtyValue()) {
             updatePlaceholderVisibility(false);
             setNeedsStyleRecalc(SubtreeStyleChange);
         }
         m_needsToUpdateViewValue = true;
         setNeedsValidityCheck();
         m_valueAttributeWasUpdatedAfterParsing = !m_parsingInProgress;
+        m_inputType->warnIfValueIsInvalid(value);
         m_inputTypeView->valueAttributeChanged();
     } else if (name == checkedAttr) {
         // Another radio button in the same group might be checked by state
         // restore. We shouldn't call setChecked() even if this has the checked
         // attribute. So, delay the setChecked() call until
         // finishParsingChildren() is called if parsing is in progress.
         if (!m_parsingInProgress && m_reflectsCheckedAttribute) {
             setChecked(!value.isNull());
             m_reflectsCheckedAttribute = true;
         }
@@ skipping 321 matching lines @@
 {
     if (isFileUpload() && !value.isEmpty()) {
         exceptionState.throwDOMException(InvalidStateError, "This input element accepts a filename, which may only be programmatically set to the empty string.");
         return;
     }
     setValue(value, eventBehavior);
 }
 
 void HTMLInputElement::setValue(const String& value, TextFieldEventBehavior eventBehavior)
 {
+    m_inputType->warnIfValueIsInvalid(value);
     if (!m_inputType->canSetValue(value))
         return;
 
     RefPtrWillBeRawPtr<HTMLInputElement> protector(this);
     EventQueueScope scope;
     String sanitizedValue = sanitizeValue(value);
     bool valueChanged = sanitizedValue != this->value();
 
     setLastChangeWasNotUserEdit();
     m_needsToUpdateViewValue = true;
@@ skipping 866 matching lines @@
 {
     return m_inputType->shouldDispatchFormControlChangeEvent(oldValue, newValue);
 }
 
 void HTMLInputElement::didNotifySubtreeInsertionsToDocument()
 {
     listAttributeTargetChanged();
 }
 
 } // namespace