Deserializing locale assumes JDK separator (underscore), does not accept RFC specified (hyphen)

[mcdee]

When deserializing a locale Jackson currently uses the underscore character as the separator rather than the dash. Specifically, in FromStringDeserializer.java line 234:

int ix = value.indexOf('_');

Many locale implementations use dash as the separator as per https://tools.ietf.org/html/rfc5646

Given the RFC states that only the characters a-z A-Z and - are valid it should be possible to leave the current code in for backward-compatibility but it should also check for '-' as a separator.

[cowtowncoder]

@mcdee Thank you for reporting this: sounds like a bug indeed.

Do you know of an existing JDK provided Locale value that would exhibit this? Would be great to have a unit test against regression, beyond fixing the issue itself.

[cowtowncoder]

Actually I think JDK always uses underscore, so I'll have to just test deserializer with made-up codes.