Excluding prereleases from a constraint doesn't work correctly

[apparentlymart]

This was originally reported over in hashicorp/terraform#33452 and so there's more context there, but the short version is that given a contradictory (and Ruby-style) constraint like 1.0.0-beta1, != 1.0.0-beta1 the resulting version set operators don't seem to be correct.

I'd expect that constraint to produce something like this...

versions.Intersection(
	versions.Released,
	versions.Only(MustParseVersion(`1.0.0-beta1`)),
	versions.All.Subtract(Only(MustParseVersion(`1.0.0-beta1`))),
),

...but instead it currently produces the following confusing expression:

versions.Union(
    versions.Only(versions.MustParseVersion("1.0.0-beta1")),
    versions.Intersection(
        versions.Released,
        versions.Only(versions.MustParseVersion("1.0.0-beta1")),
        (versions.All).Subtract(versions.Only(versions.MustParseVersion("1.0.0-beta1"))),
    )
)

This produces the wrong behavior because, after some reduction, this is effectively "1.0.0-beta1 OR NOT 1.0.0-beta1", which therefore matches -- any version is either that version or not -- when it should be requiring both and therefore reducing to an empty set.

[apparentlymart]

This is fixed in v1.0.2.