Function xmlCatalogAddLocal 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn xmlCatalogAddLocal(
    catalogs: *mut c_void,
    URL: *const xmlChar,
) -> *mut c_void

Per-document local catalog: an opaque pointer to a Vec<CatalogEntry>. xmlCatalogAddLocal returns a (possibly new) list; entries are resolved with xmlCatalogLocalResolve*; freed with xmlCatalogFreeLocal.

SAFETY

• catalogs 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.

• URL 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.