Fix to Handle downkey event on last and first radio button of a radio button list

Source/core/html/forms/RadioInputType.cpp

 /*
  * Copyright (C) 2005, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * 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
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 19 matching lines @@
 #include "core/events/MouseEvent.h"
 #include "core/html/HTMLInputElement.h"
 #include "core/page/SpatialNavigation.h"
 #include "platform/text/PlatformLocale.h"
 #include "wtf/PassOwnPtr.h"
 
 namespace blink {
 
 namespace {
 
-HTMLElement* nextElement(const HTMLElement& element, bool forward)
+HTMLElement* nextElement(const HTMLElement& element, HTMLFormElement* stayWithin, bool forward)
 {
-    return forward ? Traversal<HTMLElement>::next(element) : Traversal<HTMLElement>::previous(element);
+    return forward ? Traversal<HTMLElement>::next(element, (Node* )stayWithin) : Traversal<HTMLElement>::previous(element, (Node* )stayWithin);
 }
 
 } // namespace
 
 using namespace HTMLNames;
 
 PassRefPtrWillBeRawPtr<InputType> RadioInputType::create(HTMLInputElement& element)
 {
     return adoptRefWillBeNoop(new RadioInputType(element));
 }
@@ skipping 11 matching lines @@
 String RadioInputType::valueMissingText() const
 {
     return locale().queryString(blink::WebLocalizedString::ValidationValueMissingForRadio);
 }
 
 void RadioInputType::handleClickEvent(MouseEvent* event)
 {
     event->setDefaultHandled();
 }
 
+HTMLInputElement* RadioInputType::findNextFocusableRadioButtonInGroup(HTMLInputElement* currentElement, bool forward)
+{
+    HTMLElement* htmlElement;
+    for (htmlElement = nextElement(*currentElement, element().form(), forward); htmlElement; htmlElement = nextElement(*htmlElement, element().form(), forward)) {
+        if (!isHTMLInputElement(*htmlElement))
+            continue;
+        HTMLInputElement* inputElement = toHTMLInputElement(htmlElement);
+        if (element().form() == inputElement->form() && inputElement->type() == InputTypeNames::radio && inputElement->name() == element().name() && inputElement->isFocusable())
+            return inputElement;
+    }
+    return nullptr;
+}
+
 void RadioInputType::handleKeydownEvent(KeyboardEvent* event)
 {
     BaseCheckableInputType::handleKeydownEvent(event);
     if (event->defaultHandled())
         return;
     const String& key = event->keyIdentifier();
     if (key != "Up" && key != "Down" && key != "Left" && key != "Right")
         return;
 
     // Left and up mean "previous radio button".
     // Right and down mean "next radio button".
     // Tested in WinIE, and even for RTL, left still means previous radio button
     // (and so moves to the right). Seems strange, but we'll match it. However,
     // when using Spatial Navigation, we need to be able to navigate without
     // changing the selection.
     Document& document = element().document();
     if (isSpatialNavigationEnabled(document.frame()))
         return;
     bool forward = (key == "Down" || key == "Right");
 
     // We can only stay within the form's children if the form hasn't been demoted to a leaf because
     // of malformed HTML.
-    for (HTMLElement* htmlElement = nextElement(element(), forward); htmlElement; htmlElement = nextElement(*htmlElement, forward)) {
-        // Once we encounter a form element, we know we're through.
-        if (isHTMLFormElement(*htmlElement))
-            break;
-        // Look for more radio buttons.
-        if (!isHTMLInputElement(*htmlElement))
-            continue;
-        HTMLInputElement* inputElement = toHTMLInputElement(htmlElement);
-        if (inputElement->form() != element().form())
-            break;
-        if (inputElement->type() == InputTypeNames::radio && inputElement->name() == element().name() && inputElement->isFocusable()) {
-            RefPtrWillBeRawPtr<HTMLInputElement> protector(inputElement);
-            document.setFocusedElement(inputElement);
-            inputElement->dispatchSimulatedClick(event, SendNoEvents);
-            event->setDefaultHandled();
-            return;
+    HTMLInputElement* inputElement = findNextFocusableRadioButtonInGroup(toHTMLInputElement(&element()), forward);
+    if (!inputElement) {
+        // Traverse in reverse direction till last or first radio button
+        forward = !(forward);
+        HTMLInputElement* nextInputElement = findNextFocusableRadioButtonInGroup(toHTMLInputElement(&element()), forward);
+        while (nextInputElement) {
+            inputElement = nextInputElement;
+            nextInputElement = findNextFocusableRadioButtonInGroup(nextInputElement, forward);
         }
     }
+    if (inputElement) {
+        RefPtrWillBeRawPtr<HTMLInputElement> protector(inputElement);
+        document.setFocusedElement(inputElement);
+        inputElement->dispatchSimulatedClick(event, SendNoEvents);
+        event->setDefaultHandled();
+        return;
+    }
 }
 
 void RadioInputType::handleKeyupEvent(KeyboardEvent* event)
 {
     const String& key = event->keyIdentifier();
     if (key != "U+0020")
         return;
     // If an unselected radio is tabbed into (because the entire group has nothing
     // checked, or because of some explicit .focus() call), then allow space to check it.
     if (element().checked())
@@ skipping 65 matching lines @@
     // The work we did in willDispatchClick was default handling.
     event->setDefaultHandled();
 }
 
 bool RadioInputType::shouldAppearIndeterminate() const
 {
     return !element().checkedRadioButtonForGroup();
 }
 
 } // namespace blink