A few more fixes

src/runtime/builtin_modules/builtins.cpp

@@ -426,7 +426,7 @@ Box* sorted(Box* obj, Box* cmp, Box* key, Box** args) {
 
     BoxedList* rtn = new BoxedList();
     for (Box* e : obj->pyElements()) {
-        listAppendInternal(rtn, e);
+        listAppendInternalStolen(rtn, e);
     }
 
     listSort(rtn, cmp, key, reverse);

src/runtime/iterators.cpp

@@ -93,9 +93,11 @@ private:
 public:
     BoxIteratorIndex(T* obj) : obj(obj), index(0) {
         Py_XINCREF(obj);
-        if (obj && !hasnext(obj, index))
+        if (obj && !hasnext(obj, index)) {
+            Py_CLEAR(obj);
             *this = *end();
         }
+    }
 
     ~BoxIteratorIndex() {
         Py_XDECREF(obj);