Array.min in 2.12.12 vs 2.13.3

[kamilkloch]

Scala 2.12.12:

> println(Array(2.0, 1.0, Double.NaN).min)
NaN

Scala 2.13.3:

> println(Array(2.0, 1.0, Double.NaN).min)
1.0

Which one is correct? ;)

[Jasper-M]

There's some history on this topic #11844

[eed3si9n]

scala/scala#8721 is the PR that came out of it and it should summarize the situation.

[NthPortal]

Welcome to Scala 2.12.12 (OpenJDK 64-Bit Server VM, Java 1.8.0_265).
Type in expressions for evaluation. Or try :help.

scala> Array(2.0, 1.0, Double.NaN, 3.0).min
res0: Double = 3.0

2.13.3 is the one that's correct (or at the very least more correct). I don't believe we can backport a fix (though I could be mistaken)

[eed3si9n]

Array(2.0, 1.0, Double.NaN, 3.0).min sounds like a clear bug in Scala 2.12.12, which I think we could backport a fix to return NaN.

However, in the original example, I would argue that both are "correct" in the sense that they work as intended.

Scala 2.12.12 conforms to IEEE 754 floating point semantics, like java.lang.Math.min(1.0, Double.NaN) returning NaN.

Scala 2.13.3 on the other hand conforms to total ordering like java.lang.Double.compare being able to sort an array of Double.