mrb_str_len_to_inum: converting may not be terminated by NUL; fix #3044

src/string.c

@@ -2163,7 +2163,8 @@ mrb_str_len_to_inum(mrb_state *mrb, const char *str, size_t len, int base, int b
     n *= base;
     n += c;
     if (n > MRB_INT_MAX) {
-      mrb_raisef(mrb, E_ARGUMENT_ERROR, "string (%S) too big for integer", mrb_str_new_cstr(mrb, str));
+      mrb_raisef(mrb, E_ARGUMENT_ERROR, "string (%S) too big for integer",
+                 mrb_str_new(mrb, str, pend-str));
     }
   }
   val = n;