The Javadoc of Long.parseUnsignedLong specifies that it should throw a
NumberFormatException if "the value represented by the string is larger
than the largest unsigned long, 2^64-1."

Test:

import java.math.BigInteger;

public class UnsignedLongBug {
  public static void main(String[] args) {
    try {
      String input = "1234567890abcdef1";
      System.out.println(Long.parseUnsignedLong(input, 16));
      BigInteger maxUnsignedLong =
BigInteger.ONE.shiftLeft(64).subtract(BigInteger.ONE);
      BigInteger inputValue = new BigInteger(input, 16);
      System.out.println(maxUnsignedLong.compareTo(inputValue));
      throw new AssertionError();
    } catch (NumberFormatException expected) {
      System.out.println("Correct");
    }
  }
}


Found by:  Louis Wasserman <lowasser@google.com>