Menubar: move to next item applied focus() to too many items

`_move` was believed to specify just one item,
called `focusableTarget`.  Using the broader
selectors this would return anything matching `a` or
`button`.  This means that the next item _as well
as_ any `button`s or `a`s found thereunder would
_also_ have their focus() event fired.

Author: Steven G. Harms

tests/unit/menubar/menubar_events.js

@@ -46,4 +46,17 @@ test( "hover over a menu item with no sub-menu should close open menu", function
 	equal($(".ui-menu:visible").length, 0,  "After triggering a sub-menu, a click on a peer menu item should close the opened sub-menu");
 });
 
+test ( "_findNextFocusableTarget should find one and only one item", function() {
+	expect(2);
+
+	var element = $("#bar1").menubar(),
+		menubarWidget = element.data("ui-menubar"),
+		firstMenuItem = $("#bar1 .ui-menubar-item").eq(0),
+		expectedFocusableTarget = $("#bar1 .ui-menubar-item .ui-widget").eq(0),
+		result = menubarWidget._findNextFocusableTarget( firstMenuItem );
+
+  equal( expectedFocusableTarget[0], result[0], "_findNextFocusableTarget should return the focusable element underneath the menuItem" );
+	equal( 1, result.length, "One and only one item should be returned." );
+});
+
 })( jQuery );

ui/jquery.ui.menubar.js

@@ -476,13 +476,17 @@ $.widget( "ui.menubar", {
 		this._move( "prev", "last", event );
 	},
 
+	_findNextFocusableTarget: function( menuItem ) {
+		return menuItem.find(".ui-button");
+	},
+
 	_move: function( direction, filter, event ) {
 		var next,
 			wrapItem;
 
 		var closestMenuItem = $( event.target ).closest(".ui-menubar-item"),
 			nextMenuItem = closestMenuItem.data( direction + "MenuItem" ),
-			focusableTarget = nextMenuItem.find("a, button");
+			focusableTarget = this._findNextFocusableTarget( nextMenuItem );
 
 		if ( this.open ) {
 			if ( nextMenuItem.data("hasSubMenu") ) {