OrderedValue.== compared doubles with IEEE equality (NaN != NaN), so a NaN value never matched a NaN enumeration member and was rejected: <v>NaN</v> against xs:double restricted by <xs:enumeration value="NaN"/> is valid, and PureXML rejected it (a cardinal-rule false positive). NaN is now treated as identical to itself in value-space equality, the identity the reference (libxml2) and XSD 1.1 use throughout; an adversarial critic flagged the shared comparison (also used by key/unique and fixed), so the key/fixed behaviour was verified against xmllint: libxml2 collides two NaN unique keys and matches fixed="NaN", i.e. the same identity, so one identity == matches the reference everywhere. Ordering (<) keeps NaN incomparable, so range facets are unaffected. Found by a new generated-value facet differential (FacetValidationDifferentialTests, opt-in via FACET_DIFF) over ~10000 datatype/facet values: one FP found, zero after; the four W3C XSTS buckets held, full suite passes, SchemaDoubleEnumerationTests locks all three relations.
Mihaela Mihaljevic
7be7fa25f3