Function copyparamtable 

pub fn copyparamtable(ht: Option<&HashTable>, name: &str) -> Option<HashTable>

Port of copyparamtable(HashTable ht, char *name) from Src/params.c:596. C body: allocates a fresh paramtable via newparamtable(ht->hsize, name), sets the global outtable = nht, then scans the source via scanhashtable(ht, 0, 0, 0, scancopyparams, 0) and clears outtable on exit. Rust port returns the freshly-allocated table; the per-node clone walk requires the HashTable iterator which isn’t wired yet (callers receive the empty allocated table — same shape the C source returns when ht is empty).