Per XSD 1.0 Datatypes a simpleType's content is
(annotation?, (restriction | list | union)). The membership table admitted each
name without the cardinality, so an empty simpleType or one combining two
derivations (two unions, a union and a list, two restrictions) was accepted.
The exactly-one rule is now enforced, mirroring the named-group compositor check.
XSTS: invalid schemas accepted 537 to 527, valid schemas rejected held at 72,
instance buckets unchanged.
Mihaela Mihaljevic
dd10f32abb