On Fri, 16 Apr 2021 16:08:53 GMT, Ian Graves <[email protected]> wrote:
>> This fixes a bug where the formatting code for `%g` flags incorrectly tries
>> to round `BigDecimal` after determining whether it should be a decimal
>> numeric format or a scientific numeric format. The solution rounds before
>> determining the correct format.
>
> Ian Graves has updated the pull request incrementally with one additional
> commit since the last revision:
>
> Inlining some single use variables
src/java.base/share/classes/java/util/Formatter.java line 3827:
> 3825: if ((value.equals(BigDecimal.ZERO))
> 3826: || ((value.compareTo(BigDecimal.valueOf(1, 4)) !=
> -1)
> 3827: && (value.compareTo(BigDecimal.valueOf(1,
> -prec)) == -1))) {
Note that `compareTo` in general specifies a negative, zero, or positive return
value, but BigDecimal and BigInteger specify a return value of -1, 0, and 1. So
the code here that compares against -1 is strictly correct. However, the
BigDecimal/BigInteger.compareTo docs say "The suggested idiom..." is a relative
comparison against zero.
Indeed, the BigDecimal::compareTo method does always seem to return -1, 0, or 1
so this code is not incorrect. Well, maybe. I checked quickly and the
BigDecimal comparison logic is fairly intricate (and also runs through
BigInteger) so I might have missed something. Also, BigDecimal is subclassable,
so an override of `compareTo` might return something other than -1, 0, or 1,
even though strictly speaking this would violate the BigDecimal spec.
I'm wondering if there should be a followup bug that changes these tests to `>=
0` and `< 0`.
-------------
PR: https://git.openjdk.java.net/jdk/pull/3363
