let str coul multiple with long

src/capi/abstract.cpp

@@ -2071,8 +2071,7 @@ extern "C" PyObject* PyNumber_Long(PyObject* o) noexcept {
         return res;
     }
     if (PyLong_Check(o)) { /* A long subclass without nb_long */
-        BoxedInt* lo = (BoxedInt*)o;
-        return PyLong_FromLong(lo->n);
+        return o;
     }
     trunc_func = PyObject_GetAttr(o, trunc_name);
     if (trunc_func) {

src/runtime/str.cpp

@@ -1146,9 +1146,24 @@ extern "C" Box* strMul(BoxedString* lhs, Box* rhs) {
     assert(PyString_Check(lhs));
 
     int n;
+
+    if (PyIndex_Check(rhs)) {
+        Box* index = PyNumber_Index(rhs);
+        if (PyErr_Occurred()) {
+            throwCAPIException();
+        }
+        rhs = index;
+    }
+
     if (PyInt_Check(rhs))
         n = static_cast<BoxedInt*>(rhs)->n;
-    else
+    else if (isSubclass(rhs->cls, long_cls)) {
+        n = _PyLong_AsInt(rhs);
+        if (PyErr_Occurred()) {
+            PyErr_Clear();
+            raiseExcHelper(OverflowError, "cannot fit 'long' into index-sized integer");
+        }
+    } else
         return NotImplemented;
     if (n <= 0)
         return EmptyString;