Function xmlIsXHTML 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn xmlIsXHTML(
    systemID: *const xmlChar,
    publicID: *const xmlChar,
) -> c_int

Test whether a public/system ID pair is one of the XHTML DTDs.

UPSTREAM-PARITY

int xmlIsXHTML(const xmlChar *systemID, const xmlChar *publicID);

SAFETY

• systemID, publicID must point to valid NUL-terminated strings (or NULL where the C contract allows) for the lifetime of the call.

The caller must not race this call with concurrent mutation of the same objects from other threads (per-object state is not internally synchronized). Violating any of the above is undefined behavior.

Exercised by the C-API differential courts (courts/suites/data-abi/*-family-probe.c) and the CLI differential courts; those pass byte-for-byte against the upstream oracle.