Allow User to be injected via @AncestorInPath

core/src/main/java/hudson/model/User.java

@@ -96,7 +96,7 @@ import java.util.logging.Logger;
  * @author Kohsuke Kawaguchi
  */
 @ExportedBean
-public class User extends AbstractModelObject implements AccessControlled, Saveable, Comparable<User> {
+public class User extends AbstractModelObject implements AccessControlled, DescriptorByNameOwner, Saveable, Comparable<User> {
 
     private transient final String id;
 
@@ -574,6 +574,10 @@ public class User extends AbstractModelObject implements AccessControlled, Savea
                 && new File(getRootDir(), id).exists();
     }
 
+    public Descriptor getDescriptorByName(String className) {
+        return Jenkins.getInstance().getDescriptorByName(className);
+    }
+
     public Object getDynamic(String token) {
         for (UserProperty property: getProperties().values()) {
             if (property instanceof Action) {