Index: src/wp-admin/js/widgets.js
===================================================================
--- src/wp-admin/js/widgets.js	(revision 32884)
+++ src/wp-admin/js/widgets.js	(working copy)
@@ -117,6 +117,8 @@
 			}
 		});
 
+		var widgetHoverTimeout;
+
 		sidebars.sortable({
 			placeholder: 'widget-placeholder',
 			items: '> .widget',
@@ -125,6 +127,10 @@
 			distance: 2,
 			containment: '#wpwrap',
 			tolerance: 'pointer',
+			out : function( event, ui ) {
+				clearTimeout( widgetHoverTimeout );
+			},
+			
 			start: function( event, ui ) {
 				var height, $this = $(this),
 					$wrap = $this.parent(),
@@ -140,6 +146,10 @@
 					// Prevents jumping when dragging a widget from an open sidebar to a closed sidebar below.
 					height = ui.item.hasClass('ui-draggable') ? $this.height() : 1 + $this.height();
 					$this.css( 'min-height', height + 'px' );
+				} else {
+					widgetHoverTimeout = setTimeout( function() {
+						$wrap.removeClass('closed');
+					}, 300 );
 				}
 			},
 
Index: src/wp-content/themes/twentyfifteen/functions.php
===================================================================
--- src/wp-content/themes/twentyfifteen/functions.php	(revision 32884)
+++ src/wp-content/themes/twentyfifteen/functions.php	(working copy)
@@ -138,6 +138,26 @@
 		'before_title'  => '<h2 class="widget-title">',
 		'after_title'   => '</h2>',
 	) );
+
+	register_sidebar( array(
+		'name'          => __( 'Widget Are 1a', 'twentyfifteen' ),
+		'id'            => 'sidebar-2',
+		'description'   => __( 'Add widgets here to appear in your sidebar.', 'twentyfifteen' ),
+		'before_widget' => '<aside id="%1$s" class="widget %2$s">',
+		'after_widget'  => '</aside>',
+		'before_title'  => '<h2 class="widget-title">',
+		'after_title'   => '</h2>',
+	) );
+
+	register_sidebar( array(
+		'name'          => __( 'Widget Are 1a', 'twentyfifteen' ),
+		'id'            => 'sidebar-3',
+		'description'   => __( 'Add widgets here to appear in your sidebar.', 'twentyfifteen' ),
+		'before_widget' => '<aside id="%1$s" class="widget %2$s">',
+		'after_widget'  => '</aside>',
+		'before_title'  => '<h2 class="widget-title">',
+		'after_title'   => '</h2>',
+	) );
 }
 add_action( 'widgets_init', 'twentyfifteen_widgets_init' );