eclipse/jetty.project — comment on commit 8de385992e3c1821b826c132f9e8d2b171b1b56e
File: jetty-webapp/src/main/java/org/eclipse/jetty/webapp/WebAppContext.java line 701
By codahale:

FWIW, `instanceof` always returns `false` for `null` values.

> At run time, the result of the `instanceof` operator is `true` if the value of the RelationalExpression is not `null` and the reference could be cast (§15.16) to the ReferenceType without raising a `ClassCastException`. Otherwise the result is false.

(http://java.sun.com/docs/books/jls/third_edition/html/expressions.html#15.20.2)