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..e86d16d41a4433ceac9be33a2cfc8fde61280ba0 100644
--- a/Source/core/html/forms/RadioInputType.cpp
+++ b/Source/core/html/forms/RadioInputType.cpp
@@ -71,6 +71,29 @@ void RadioInputType::handleClickEvent(MouseEvent* event)
     event->setDefaultHandled();
 }
 
+HTMLElement* RadioInputType::findNextFocusableRadioButton(HTMLInputElement* currentHtmlInputElement, bool forward)

[keishi, 2014/09/26 04:25:35]

I'm sorry. I know I wrote HTMLElement* in my previous comment, but this always
returns an input element so returning a HTMLInputElement* is probably better.

+{
+    HTMLElement* htmlElement;
+    for (htmlElement = nextElement(*currentHtmlInputElement, forward); htmlElement; htmlElement = nextElement(*htmlElement, forward)) {
+        // Once we encounter a form element, we know we're through.
+        if (isHTMLFormElement(*htmlElement)) {

[keishi, 2014/09/26 04:25:35]

No curly braces for single line if statements.

[keishi, 2014/09/26 04:25:35]

As I said in my previous comment, this isn't right.

We might have other form elements as a descendent of the associated form and
those should just be ignored.

The set of elements to cycle should match the RadioNodeList you get from the
form element.
Here is the test case I used.
http://jsbin.com/tumeculiheku/7

Traversal::next can take a node to stay inside as its second argument. You can
pass element() in there.
Something like this:

HTMLElement* nextElement(const HTMLElement& element, HTMLElement* stayWithin,
bool forward)
{
    return forward ? Traversal<HTMLElement>::next(element, stayWithin) :
Traversal<HTMLElement>::previous(element, stayWithin);
}

for (htmlElement = nextElement(*currentHtmlInputElement, element().form(),
forward); htmlElement; htmlElement = nextElement(*htmlElement, element().form(),
forward)) {...}

+            return nullptr;
+        }
+        // Look for more radio buttons.
+        if (!isHTMLInputElement(*htmlElement)) {

[keishi, 2014/09/26 04:25:35]

Ditto.

+            continue;
+        }
+        HTMLInputElement* inputElement = toHTMLInputElement(htmlElement);
+        if (inputElement->form() != currentHtmlInputElement->form()) {

[keishi, 2014/09/26 04:25:35]

We should be checking if form equals element().form(), not the form for
currentHtmlInputElement.

[keishi, 2014/09/26 04:25:35]

Ditto.

+            return nullptr;
+        }
+        if (inputElement->isRadioButton() && inputElement->name() == currentHtmlInputElement->name() && inputElement->isFocusable()) {

[keishi, 2014/09/26 04:25:35]

Ditto.

+            return htmlElement;
+        }
+    }
+    return nullptr;
+}
+
 void RadioInputType::handleKeydownEvent(KeyboardEvent* event)
 {
     BaseCheckableInputType::handleKeydownEvent(event);
@@ -93,24 +116,24 @@ 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))
-            break;
-        // Look for more radio buttons.
-        if (!isHTMLInputElement(*htmlElement))
-            continue;
-        HTMLInputElement* inputElement = toHTMLInputElement(htmlElement);
-        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;
+    HTMLElement* htmlElement = findNextFocusableRadioButton(toHTMLInputElement(&element()), forward);
+    if (!htmlElement) {
+        // Traverse in reverse direction till last or first radio button
+        forward = !(forward);
+        HTMLElement* nextHtmlElement = findNextFocusableRadioButton(toHTMLInputElement(&element()), forward);
+        while (nextHtmlElement) {
+            htmlElement = nextHtmlElement;
+            nextHtmlElement = findNextFocusableRadioButton(toHTMLInputElement(nextHtmlElement), forward);
         }
     }
+    if (htmlElement) {
+        HTMLInputElement* inputElement = toHTMLInputElement(htmlElement);
+        RefPtrWillBeRawPtr<HTMLInputElement> protector(inputElement);
+        document.setFocusedElement(inputElement);
+        inputElement->dispatchSimulatedClick(event, SendNoEvents);
+        event->setDefaultHandled();
+        return;
+    }
 }
 
 void RadioInputType::handleKeyupEvent(KeyboardEvent* event)