RFR for bug JDK-8030690 TEST_BUG java/nio/Buffer/Chars.java fails intermittently

[Eric Wang]

Hi Everyone,

I'm working on the bug https://bugs.openjdk.java.net/browse/JDK-8030690.
The test failed due to there's a logic fault in randomizeRange(), if 
cb.capacity() returns 1 then mid = cb.capacity() >>> 1 which is 0. it 
causes Random.nextInt(0) throws the IllegalArgumentException.

So the suggested fix is to update the randomizeRange() like below.

     static CharBuffer randomizeRange(CharBuffer cb) {
         int mid = cb.capacity() >>> 1;
         int start = RAND.nextInt(mid + 1); // from 0 to mid
         int end = mid + RAND.nextInt(cb.capacity() - mid + 1); // from 
mid to capacity.
         cb.position(start);
         cb.limit(end);
         return cb;
     }

Please let me know if you have any comment. The webrev will be sent soon.

Thanks,
Eric