Weird issues validating prescoped attribute values in Shibboleth SP 2.5.5

[Nick Roy]

Hello,

I'm asserting ePPN and eduPersonScopedAffiliation from an IdP with a scope declared in metadata of 'example.com'.  The SP has a local copy of this IdP metadata and loads and processes the following released attributes:

uid
ePPN
mail

eduPersonScopedAffiliation is also released, but it is seemingly getting blocked both by the scoping rule in attribute-policy.xml and the ScopedAttributeDecoder.

Values for ePSA and ePPN are set in my directory with a scope of 'example.com' already on them.  The attribute-resolver.xml on the IdP side has these attributes defined as 'Prescoped' types.

When I remove the scoping rule for scoped affiliations and change the attribute-map definition for this attribute from ScopedAttributeDecoder to StringAttributeDecoder, I see unscoped values in the headers set on the SP web server.  When I set this back to ScopedAttributeDecoder, the values get rejected as being unscoped:
2015-11-05 13:09:42 WARN Shibboleth.AttributeDecoder.Scoped [1]: ignoring unscoped AttributeValue
2015-11-05 13:09:42 WARN Shibboleth.AttributeDecoder.Scoped [1]: ignoring unscoped AttributeValue


I'm wondering if the IdP is ripping the scope off of the eduPersonScopedAffiliation.  If it's doing this, why isn't it doing the same with ePPN?

Thanks,

Nick