diff -r efd9c589177a -r c0b4a8b5a012 toolkit/javascript/d3/src/core/selection-property.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/javascript/d3/src/core/selection-property.js	Thu Apr 10 14:20:23 2014 +0200
@@ -0,0 +1,23 @@
+d3_selectionPrototype.property = function(name, value) {
+
+  // If no value is specified, return the first value.
+  if (arguments.length < 2) return this.node()[name];
+
+  function propertyNull() {
+    delete this[name];
+  }
+
+  function propertyConstant() {
+    this[name] = value;
+  }
+
+  function propertyFunction() {
+    var x = value.apply(this, arguments);
+    if (x == null) delete this[name];
+    else this[name] = x;
+  }
+
+  return this.each(value == null
+      ? propertyNull : (typeof value === "function"
+      ? propertyFunction : propertyConstant));
+};