simconvoi.cc: Too small buffer size may cause crashing

[z9999+]

This was reported in japanese community.
If convoi name is too long, it will cause crashing when the convoi entered a depot.

I searched other buffer size of add_message(). In other places, it is at least 256 bytes.
This is the only one which using 128 bytes buffer, and if convoi name is too long, it will cause crashing.
(Japanese character needs 3 bytes for each.)

simconvoi.cc:1074-

      // ok, we are entering a depot
      char buf[128];

      // we still book the money for the trip; however, the frieght will be lost
      calc_gewinn();

      akt_speed = 0;
      sprintf(buf, translator::translate("!1_DEPOT_REACHED"), get_name());
      welt->get_message()->add_message(buf, v->get_pos().get_2d(),message_t::convoi, PLAYER_FLAG|get_besitzer()->get_player_nr(), IMG_LEER);

[prissi]

cbuffer_t will be anyway the better solution. Thank you.

[Isaac Eiland-Hall]

I'm sorry to spam up the report - but I just gotta say: >128char convoi name?!?! Wow!

[DirrrtyDirk]

actually 128 byte - and:

(Japanese character needs 3 bytes for each.)

But still... I thought in Japanese, names and words need fewer characters than in English or other Western languages... (e.g. "Shin-Ōsaka Station" = 新大阪駅 ) 18 in English and 4(x3=12) in Japanese... yep, needing more than 128 bytes is still impressive to me. 

[prissi]

The default name of a convoi is the first engine. Thus some long names may happen. Anyway, for netowrk mode which could ultimatively result in exploits due to buffer overruns detecting such bugs is very good.

[Ters]

I guess this is why the message I get when a convoy enters a depot looks messed up now. Since sprintf is not used anymore, all the translations have to be rewritten. Alternatively allocate a buffer that is the size of the message and the name and then sprintf into that, but sprintf is a dangerous function.

[prissi]

Ups, sorry, will be corrected.