Actualización

web/assets/modernizr/feature-detects/css-positionsticky.js

@@ -0,0 +1,13 @@
+// Sticky positioning - constrains an element to be positioned inside the
+// intersection of its container box, and the viewport.
+Modernizr.addTest('csspositionsticky', function () {
+
+    var prop = 'position:';
+    var value = 'sticky';
+    var el = document.createElement('modernizr');
+    var mStyle = el.style;
+
+    mStyle.cssText = prop + Modernizr._prefixes.join(value + ';' + prop).slice(0, -prop.length);
+
+    return mStyle.position.indexOf(value) !== -1;
+});