Function list_append 

pub unsafe fn list_append(l: *mut List, data: *mut c_void) -> c_int

Append data to the end of the list (alias for push_back).

UPSTREAM-PARITY

int xmlListAppend(xmlListPtr l, void *data);

SAFETY

• l, data 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.