private final byte[] rowBytes(int i) {
    if (i == -1) {
      return HConstants.EMPTY_BYTE_ARRAY;
    }
    return Bytes.toBytes(rowStr(i));
  }
Disable this when this test fails hopelessly and you need to debug a simpler case.
hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestSeekOptimizations.java