Function xmlParserError 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn xmlParserError(
    ctx: *mut c_void,
    msg: *const c_char,
)

Default SAX v1 error handler — void xmlParserError(void *ctx, const char *msg, ...).

UPSTREAM-PARITY: the candidate exposes the non-variadic ABI (fn(ctx, msg)); variadic formatting is not reproducible on stable Rust (documented safe divergence — callers pass pre-formatted messages).

SAFETY

• ctx may be NULL (unused by the candidate’s legacy path).
• msg must be a valid NUL-terminated C string or NULL.