Function xmlTextReaderSchemaValidate 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn xmlTextReaderSchemaValidate(
    reader: *mut XmlTextReader,
    xsd: *const c_char,
) -> c_int

int xmlTextReaderSchemaValidate(xmlTextReaderPtr reader, const char *xsd) — parse xsd and validate the reader’s document as it is processed.

UPSTREAM-PARITY (xmlreader.c xmlTextReaderSchemaValidateInternal): activation is only possible before the first Read(); the schema is compiled NOW (a compile failure returns -1, which php reports as “Schema contains errors”) and the document is validated at read time — validity diagnostics surface on the reader’s error channel while Read() streams, not as this call’s return value.

SAFETY

• xsd must be a valid path or NULL.