RFR 8199258: BigInteger.bitLength() should explicitly specify behavior when the value is zero

[Roger Riggs]

+1, looks fine.

Roger

On 3/7/2018 2:21 PM, Brian Burkhalter wrote:
> https://bugs.openjdk.java.net/browse/JDK-8199258
>
> A diff is included below. If this looks good then a CSR will follow.
>
> Thanks,
>
> Brian
>
> --- a/src/java.base/share/classes/java/math/BigInteger.java
> +++ b/src/java.base/share/classes/java/math/BigInteger.java
> @@ -1,5 +1,5 @@
>   /*
> - * Copyright (c) 1996, 2016, Oracle and/or its affiliates. All rights reserved.
> + * Copyright (c) 1996, 2018, Oracle and/or its affiliates. All rights reserved.
>    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
>    *
>    * This code is free software; you can redistribute it and/or modify it
> @@ -3556,8 +3556,8 @@
>        * Returns the number of bits in the minimal two's-complement
>        * representation of this BigInteger, <em>excluding</em> a sign bit.
>        * For positive BigIntegers, this is equivalent to the number of bits in
> -     * the ordinary binary representation.  (Computes
> -     * {@code (ceil(log2(this < 0 ? -this : this+1)))}.)
> +     * the ordinary binary representation.  For zero this method returns
> +     * {@code 0}.  (Computes {@code (ceil(log2(this < 0 ? -this : this+1)))}.)
>        *
>        * @return number of bits in the minimal two's-complement
>        *         representation of this BigInteger, <em>excluding</em> a sign bit