A bit of introduction - we as a jug (java user group) got more active at the end of 2013 in no small part thanks to Ivan. We managed to build openjdk, import it in 3 major IDEs (eclipse, intellij and netbeans) and contributed a Virtual Machine with buildable openjdk 9 (both in fedora and ubuntu) and organized a couple of events, we decided we were ready for the next part.
At the end of 2014 we started timidly to try to contribute in the Adopt OpenJDK program. Adopt OpenJDK allows everyone* to participate in building and writing the java platform itself (or at least that's how we understood it *back then*).
We knew that LJC (London Java Community - their most popular jug) heavily participated in the new Date/Time API and soujava (Brasil's most popular jug) also managed to include code in the OpenJDK. Elated by these guys' successes we decided we had enough free time and sheer energy to contribute to the OpenJDK and thus put ourselves on the OpenJDK map.
In December 2014 we asked for something to work on. Nobody answered.
We decided to work on a simple Throwable convenience method (JDK-5050783). We had a hackaton. We submitted our fix. We were given some feedback and we submitted another. And we were told not to play with grown up stuff. That was a bit discouraging. But we didn't give up.
In February 2015 we started working on jaxp warnings. We fixed 43 easy warnings and submitted a patch. Then we fixed more harder warnings and submitted another patch. The great Joe Darcy answered but unfortunately we got nowhere again. That sucks.
A bit before that (Dec 2014) jug.bg member Doychin Bonzhev found a bug in the NetworkInterface and submitted a solution. He even submitted to another mail-list. He got a response (saying it is reasonable solution) and answered, but that was it. Nothing AFAIK followed.
So that was it for us. We gave up. Probably we didn't know the right people, but I argue that shouldn't matter. From time to time we get mentioned as collaborators in the Adopt OpenJDK by our dear friend Mani. We don't feel like that at all.
* Now you understand why the asterisk, right?