Function xmlMemRealloc 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn xmlMemRealloc(
    ptr: *mut c_void,
    size: usize,
) -> *mut c_void

Reallocate memory through the debug allocator (upstream xmlmemory.h).

void *xmlMemRealloc(void *ptr, size_t size);

C realloc semantics + registry maintenance (upstream xmlMemRealloc: NULL ptr allocates, failure leaves the old block recorded and intact).

SAFETY

• ptr 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.