message: eosio.token: limit memo size
diff: @@ -33,6 +33,7 @@ void token::issue( account_name to, asset quantity, string memo )
  {
  auto sym = quantity.symbol;
  eosio_assert( sym.is_valid(), "invalid symbol name" );
  + eosio_assert( memo.size() <= 256, "memo has more than 256 bytes" );
  auto sym_name = sym.name();
  stats statstable( _self, sym_name );
  @@ -61,7 +62,7 @@ void token::issue( account_name to, asset quantity, string memo )
  void token::transfer( account_name from,
  account_name to,
  asset quantity,
  - string /*memo*/ )
  + string memo )
  {
  eosio_assert( from != to, "cannot transfer to self" );
  require_auth( from );
  @@ -76,6 +77,7 @@ void token::transfer( account_name from,
  eosio_assert( quantity.is_valid(), "invalid quantity" );
  eosio_assert( quantity.amount > 0, "must transfer positive quantity" );
  eosio_assert( quantity.symbol == st.supply.symbol, "symbol precision mismatch" );
  + eosio_assert( memo.size() <= 256, "memo has more than 256 bytes" );
  sub_balance( from, quantity, st );
  