The shopspring/decimal package provides a NullDecimal struct intended
for use with nullable SQL NUMERICs and numbers. It has Scanner and
Valuer implementations already, but adding it to this package allows
it to be used with the binary encoding as well.
The implementation is very straightforward, but the tests have been made
slightly more complicated. The previous version wasn't testing the
decimal.Decimal cases, and this change adds those as well as new
NullDecimal cases. I've added some logic to the test harness to catch
these as you need to use the Equals method to properly compare Decimals.
Bug was advancing the read pointer by the length of the value even if it
was a NULL value. Since NULL is indicated by a -1 length it actually
decremented the read pointer.
Original issue https://github.com/jackc/pgtype/issues/68
This crash occurred in the recursive assignment system used to support
multidimensional arrays.
This was fixed in 9639a69d451f55456f598c1aa8b93053f8df3088. However,
that fix incorrectly used nil instead of an empty slice.
In hindsight, it appears the fundamental error is that an assignment to
a slice of a type that is not specified is handled with the recursive /
reflection path. Or another way of looking at it is as an unexpected
feature where []T can now be scanned if individual elements are
assignable to T even if []T is not specifically handled.
But this new reflection / recursive path did not handle empty arrays.
This fix handles the reflection path for an empty slice by allocating an
empty slice.
When nil IP is returned from net.ParseIP, it is accepted into Inet type,
but not properly marked as being Null. That introduces issues later on
when calling for example EncodeBinary, since it does not assume this can
happen.
This commit resolves that by properly detecting zero-length net.IP and
setting status to Null if that is the case.
