Function validate_one_attribute 

pub unsafe fn validate_one_attribute(
    ctxt: *mut _xmlValidCtxt,
    doc: *mut _xmlDoc,
    elem: *mut _xmlNode,
    attr: *mut _xmlAttr,
    value: *const xmlChar,
) -> c_int

Upstream xmlValidateOneAttribute(ctxt, doc, elem, attr, value).

Performs [VC: Attribute Value Type], [VC: Fixed Attribute Default], [VC: ID], [VC: IDREF], [VC: Notation Attributes], [VC: Enumeration], and the ENTITY existence check via xmlValidateAttributeValue2.

SAFETY

• ctxt/doc may be NULL; elem/attr/value valid pointers or NULL.