[io] Encoding bug in XmlStreamReader in Commons IO 2.14.0?

[Laurence Gonsalves]

Hello,

It looks like XmlStreamReader is not correctly handling several encodings
in Commons IO 2.14.0 that previously worked in version 2.13.0.

Here's a self-contained snippet (Kotlin) that demonstrates the problem:

    val xml = "<?xml version='1.0' encoding='437'?><root>Ç</root>"

    val stream = xml.byteInputStream(Charset.forName("437"))

    val reader = XmlStreamReader.builder()
        .setInputStream(stream)
        .setLenient(false)
        .get()

    reader.readText() shouldBe xml

With 2.13.0 this code works fine, but in 2.14.0 the "Ç" (C-cedilla) becomes
a "�" (Unicode replacement character).

We're seeing similar issues with all of the other code page encodings we've
tried (850, 852, 855, 857, 860, 861, 862, 863, 865, and 866).