Ticket #40492: 40492.2.diff

src/wp-content/themes/twentyfifteen/js/functions.js

@@ -99 +99 @@
                 var windowPos = $window.scrollTop(),
                         windowHeight = $window.height(),
                         sidebarHeight = $sidebar.height(),
-                        bodyHeight = $body.height();
+                        pageHeight = $( '#page' ).height();
 
-                if( 955 < $window.width() && bodyHeight > sidebarHeight && ( windowPos + windowHeight ) >= sidebarHeight ) {
+                if( 955 < $window.width() && pageHeight > sidebarHeight && ( windowPos + windowHeight ) >= sidebarHeight ) {
                         $sidebar.css({
                                 position: 'fixed',
                                 bottom: sidebarHeight > windowHeight ? 0 : 'auto'