ClassCastException on collection generics for jdk8 working code

[Emanuel]

Thank you Martijn, i didn't know :)

here we go :
https://gist.github.com/tglman/02eb98fb1c80386fa3ab
https://gist.github.com/tglman/44b0b3fc4239d9229027

Let me add also that OrientDB don't rely in any way on this behavior, it
come out just from two not well written legacy test case ;).

On 01/17/2015 05:11 PM, Martijn Verburg wrote:
> Hi Emanuel,
>
> Good to see you today! OpenJDK mailing lists strip attachments so
> you'll need to give a pastebin link or similar.
>
> Cheers,
> Martijn
>
> On 17 January 2015 at 16:58, Emanuel <emanuele.tagliaferri at gmail.com
> <mailto:emanuele.tagliaferri at gmail.com>> wrote:
>
>     I am at the Adopt OpenJdk hack day organized by the LJC, I am running
>     tests cases of OrientDB (open source java based NoSql) on JDK9 (Build
>     b45 ), and i got some issue with the use of generics.
>
>     basically this code:
>             List<Date> list = new ArrayList<>();
>             list.add(new Date());
>
>             List<Foo> cList = (List<Foo>) (List<?>) list;
>             Date date = (Date) cList.get(0);                        // it
>     fail here
>
>     on jdk8 it work fine, on jdk9 the code fail in the marked line.
>
>     the jdk8 bytecode for the failing line is:
>           invokeinterface #7,  2            // InterfaceMethod
>     java/util/List.get:(I)Ljava/lang/Object;
>           checkcast     #4                  // class java/util/Date
>
>     instead of  on jdk9 is:
>           invokeinterface #7,  2            // InterfaceMethod
>     java/util/List.get:(I)Ljava/lang/Object;
>           checkcast     #8                  // class ListFail$Foo
>           checkcast     #4                  // class java/util/Date
>
>
>     and is clear that there's a additional cast that is causing the
>     exception.
>
>     I understand that this code is not the exactly clean and correct
>     conceptually, but it may be a lot of this staff out there that can be
>     break by jdk9.
>
>     In attachment a couple of simple example for reproduce this issue.
>
>
>     Regards
>
>     Emanuel
>
>
>