[bugfix] new_uniq_sym must take one more byte chunk for new string
[bugfix] new_uniq_sym must take one more byte chunk for new string

dcurrie/picrin,picrin-scheme/picrin,koba-e964/picrin,omasanori/picrin,koba-e964/picrin,omasanori/picrin,ktakashi/picrin,picrin-scheme/picrin,leavesbnw/picrin,dcurrie/picrin,leavesbnw/picrin,leavesbnw/picrin,koba-e964/picrin,ktakashi/picrin,ktakashi/picrin