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

Source/core/html/forms/RadioInputType.cpp

Index: Source/core/html/forms/RadioInputType.cpp
diff --git a/Source/core/html/forms/RadioInputType.cpp b/Source/core/html/forms/RadioInputType.cpp
index 4e992f650156e2874b2a8c1e9af574347c232a5a..3cfe703954a62957d096f998c3f10a9dfede02a0 100644
--- a/Source/core/html/forms/RadioInputType.cpp
+++ b/Source/core/html/forms/RadioInputType.cpp
@@ -93,10 +93,23 @@ void RadioInputType::handleKeydownEvent(KeyboardEvent* event)
 
     // 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))
+    HTMLElement* htmlElement;
+    bool reachedAtEnd = false;

[keishi, 2014/09/24 04:32:27]

nit: I think reachedEnd is better.

+    for (htmlElement = nextElement(element(), forward); ; htmlElement = nextElement(*htmlElement, forward)) {
+        // Once we encounter no element OR an input element of other form
+        // OR form element in backward traversal, we know we're through.
+        if (!htmlElement) {
+            reachedAtEnd = true;
             break;
+        }
+        if ((isHTMLInputElement(*htmlElement) && toHTMLInputElement(htmlElement)->form() != element().form())) {

[keishi, 2014/09/24 04:32:28]

Why do we end the search? I think we should just ignore radio buttons with
different associated forms.

+            reachedAtEnd = true;
+            break;
+        }
+        if (isHTMLFormElement(*htmlElement)) {

[keishi, 2014/09/24 04:32:27]

I know this was here from before but this seems wrong.
The associated form element of this control may have a form element as one of
its descendants.

I think we should be using the stayWithin argument for Traversal::next to
traverse within the associated form element.

+            reachedAtEnd = true;
+            break;
+        }
         // Look for more radio buttons.
         if (!isHTMLInputElement(*htmlElement))
             continue;
@@ -104,13 +117,32 @@ void RadioInputType::handleKeydownEvent(KeyboardEvent* event)
         if (inputElement->form() != element().form())
             break;
         if (inputElement->isRadioButton() && inputElement->name() == element().name() && inputElement->isFocusable()) {
-            RefPtrWillBeRawPtr<HTMLInputElement> protector(inputElement);
-            document.setFocusedElement(inputElement);
-            inputElement->dispatchSimulatedClick(event, SendNoEvents);
-            event->setDefaultHandled();
-            return;
+            break;
+        }
+    }
+    if (reachedAtEnd) {
+        // Traverse in reverse direction till last or first radio button
+        forward = !(forward);
+        htmlElement = &element();
+        HTMLElement* nextHtmlElement = nextElement(*htmlElement, forward);
+        HTMLInputElement* inputElement;
+        while (nextHtmlElement && !isHTMLFormElement(*nextHtmlElement)) {
+            if (isHTMLInputElement(*nextHtmlElement)) {
+                inputElement = toHTMLInputElement(nextHtmlElement);
+                if (inputElement->form() == element().form() && inputElement->isRadioButton() && inputElement->name() == element().name() && inputElement->isFocusable())

[keishi, 2014/09/24 04:32:27]

This code is mostly same from the for loop above. Could you share the code by
adding a method like: 
HTMLElement* findNextFocusableRadioButton(bool forward)

+                    htmlElement = nextHtmlElement;
+            }
+            nextHtmlElement = nextElement(*nextHtmlElement, forward);
         }
     }
+    HTMLInputElement* inputElement = toHTMLInputElement(htmlElement);
+    if (inputElement->isRadioButton() && inputElement->name() == element().name() && inputElement->isFocusable()) {

[keishi, 2014/09/24 04:32:28]

Isn't this checking the same thing twice? We already checked this in the for
loop and while loop.

+        RefPtrWillBeRawPtr<HTMLInputElement> protector(inputElement);
+        document.setFocusedElement(inputElement);
+        inputElement->dispatchSimulatedClick(event, SendNoEvents);
+        event->setDefaultHandled();
+        return;
+    }
 }
 
 void RadioInputType::handleKeyupEvent(KeyboardEvent* event)