use="prohibited" removes an attribute from a complex type's effective {attribute
uses} (XSD 1.0 §3.4.2): the attribute is then undeclared, so its presence is
rejected when no attribute wildcard admits it (attJ), but is still admitted (and
validated per the wildcard's processContents) when one does (attZ002). The use
had been parsed as merely optional, so a prohibited attribute was always allowed.
AttributeUse gains a `prohibited` flag, set for both a local declaration and an
<attribute ref> use site. The declaration is kept in the type's attribute list so
schema-validity checks still see it, while instance validation excludes prohibited
uses: the matching loop and the wildcard's declared-set skip them, and the ID-type
count ignores them. There is no explicit "prohibited attribute present" error, so
a wildcard that admits the attribute name still governs it (an earlier attempt to
reject outright wrongly overrode the wildcard).
invalid-instances-accepted 43 to 39, no false positive (valid-instances-rejected
and valid-schemas-rejected held at 0, invalid-schemas-accepted unchanged at 69).
An adversarial review confirmed prohibited attributes admitted by a wildcard
(every namespace/processContents variation, local and ref), restriction removal,
and the ID-count interaction are all handled without over-rejection.
Mihaela Mihaljevic
488f58701a