Function validate_attribute_decl 

pub unsafe fn validate_attribute_decl(
    ctxt: *mut _xmlValidCtxt,
    doc: *mut _xmlDoc,
    elem: *mut _xmlNode,
    attr: *mut _xmlAttribute,
) -> c_int

Validate an attribute’s value against its declaration.

UPSTREAM-PARITY

int xmlValidateAttributeDecl(xmlValidCtxtPtr ctxt,
                             xmlDocPtr doc,
                             xmlNodePtr elem,
                             xmlAttributePtr attr);

Checks:

• Attribute value type (CDATA, ID, IDREF, etc.)
• Enumeration membership
• NOTATION declaration
• Default value validity

Returns 1 if valid, 0 otherwise.

SAFETY

• ctxt, doc, elem, attr may be NULL.