If an anonymous class calls a method ITD'd onto one of its own
supertypes (e.g. new A() { xx(null); }) then it can be reported
as an ambiguous method invocation on Java8. There is different
handling for Java8 that is revealing an issue. The intertype
method declarations are recorded in a member finder attached to the
target type (A in this case). When the local type binding is
built it gets all the methods from supertypes added to it - this
unfortunately includes the ITD method. Then later when something
asks for all 'xx' methods on A, it finds the ITD method from when
A was constructed and an additional copy from the member finder.
The quick fix is for the member finder to use a set rather than
list when answering 'what are the xx methods'. If this proves
a problem down the line the deeper fix would be to avoid including
ITDs when the local type binding is built.
Andy Clement