Given the following code
----
                    public class ChildClass extends UndefinedClass
                        implements UndefinedInterface, Iterable {

                    }
---
when the javadoc is generated with --ignore-source-errors
then the generated javadoc contains 'ChildClass extends UndefinedClass implements Iterable' but there is no mention of UndefinedInterface.

This may be a correct behaviour as there is no way to tell which methods implement UndefinedInterface or we may want to generate 'implements UndefinedInterface'