Function xmlTextReaderQuoteChar 

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

int xmlTextReaderQuoteChar(xmlTextReaderPtr reader).

UPSTREAM-PARITY: libxml2 2.13/2.15 returns '"' unconditionally for any non-NULL reader (the implementation is a placeholder that does not inspect the attribute; see the /* TODO maybe lookup the attribute value */ comment in xmlreader.c). The candidate reproduces that historical behavior exactly.

SAFETY

• reader must be valid pointers (or NULL where the upstream C contract allows), obtained from the matching constructor/owner and not yet freed; the callee may take or keep ownership exactly as the C API specifies.

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.