web/src/main/java/org/springframework/security/web/util/OnCommittedResponseWrapper.java
@Override
	public final void sendError(int sc, String msg) throws IOException {
		doOnResponseCommitted();
		super.sendError(sc, msg);
	}
@Override
	public final void sendError(int sc, String msg) throws IOException {
		doOnResponseCommitted();
		super.sendError(sc, msg);
	}
Makes sure {@link OnCommittedResponseWrapper#onResponseCommitted()} is invoked
before calling the superclass <code>sendError()</code>