Crash in game::activity_on_finish when crafting clean water interrupted by zombie

[dholmes215]

I was crafting clean water "as long as possible" when a zombie child interrupted me. I don't remember if I tried to continue or quit right there.

(gdb) bt
#0  0x000000010059c58d in game::activity_on_finish (this=0x6fffff90010) at src/game.cpp:1843
#1  0x000000010059b3b2 in game::process_activity (this=0x6fffff90010) at src/game.cpp:1585
#2  0x00000001005998de in game::do_turn (this=0x6fffff90010) at src/game.cpp:1419
#3  0x00000001009c276a in main (argc=0, argv=0x22ab38) at src/main.cpp:290
(gdb) l
1838            break;
1839        case ACT_LONGCRAFT:
1840            complete_craft();
1841            u.activity.type = ACT_NULL;
1842            {
1843                int batch_size = u.activity.values.front();
1844                if( making_would_work( u.lastrecipe, batch_size ) ) {
1845                    make_all_craft(u.lastrecipe, batch_size);
1846                }
1847            }
(gdb) print u.activity
$2 = {
  <JsonSerializer> = {
    _vptr.JsonSerializer = 0x100d11730 <vtable for player_activity+16>
  },
  <JsonDeserializer> = {
    _vptr.JsonDeserializer = 0x100d11760 <vtable for player_activity+64>
  },
  members of player_activity:
  type = ACT_NULL,
  moves_left = 0,
  index = -1,
  position = -2147483648,
  name = {
    static npos = <optimized out>,
    _M_dataplus = {
      <std::allocator<char>> = {
        <__gnu_cxx::new_allocator<char>> = {<No data fields>}, <No data fields>},
      members of std::basic_string<char, std::char_traits<char>, std::allocator<char> >::_Alloc_hider:
      _M_p = 0x3fefbfc38 <cygstdc++-6!_ZNSs4_Rep20_S_empty_rep_storageE+24> ""
    }
  },
  ignore_trivial = false,
  values = {
    <std::_Vector_base<int, std::allocator<int> >> = {
      _M_impl = {
        <std::allocator<int>> = {
          <__gnu_cxx::new_allocator<int>> = {<No data fields>}, <No data fields>},
        members of std::_Vector_base<int, std::allocator<int> >::_Vector_impl:
        _M_start = 0x0,
        _M_finish = 0x0,
        _M_end_of_storage = 0x0
      }
    }, <No data fields>},
  str_values = {
    <std::_Vector_base<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >> = {
      _M_impl = {
        <std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >> = {
          <__gnu_cxx::new_allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >> = {<No data fields>}, <No data fields>},
        members of std::_Vector_base<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> >                                                            > >::_Vector_impl:
        _M_start = 0x0,
        _M_finish = 0x0,
        _M_end_of_storage = 0x0
      }
    }, <No data fields>},
  placement = {
    <JsonSerializer> = {
      _vptr.JsonSerializer = 0x100d128b0 <vtable for point+16>
    },
    <JsonDeserializer> = {
      _vptr.JsonDeserializer = 0x100d128e0 <vtable for point+64>
    },
    members of point:
    x = -1,
    y = -1
  },
  warned_of_proximity = false,
  auto_resume = false
}

[dholmes215]

This was basically 0.B, build by me in Cygwin.

[kevingranade]

I haven't had any luck reproducing it, the only possibility that jumps out at me is that the implicit player_activity() constructor called by player::cancel_activity() isn't clearing player_activity::type.
Unfortunately can't test this theory without a reproduction case.

[kevingranade]

Managed to reproduce, yay? No closer to figuring out what's happening though, deduction tells me something in player::complete_craft() is resetting the activity.

[kevingranade]

Wow that's just odd, here's the backtrace:

#0 player::cancel_activity (this=0xf74d91d4) at src/player.cpp:12614
#1 0x081fbc25 in game::cancel_activity_query (this=0xf7488008, message=0x8a1ce12 "%s spotted!") at src/game.cpp:1658
#2 0x08218d9f in game::mon_info (this=0xf7488008, w=0x9b83b88) at src/game.cpp:5717
#3 0x08215852 in game::draw_sidebar (this=0xf7488008) at src/game.cpp:5027
#4 0x082149d8 in game::draw (this=0xf7488008) at src/game.cpp:4915
#5 0x08216871 in game::refresh_all (this=0xf7488008) at src/game.cpp:5160
#6 0x0823836c in game::handle_liquid (this=0xf7488008, liquid=..., from_ground=false, infinite=false, source=0x0, cont=0x0) at src/game.cpp:9821
#7 0x088174c5 in set_item_inventory (newit=...) at src/crafting.cpp:1580
#8 0x08816bce in player::complete_craft (this=0xf74d91d4) at src/crafting.cpp:1537
#9 0x080e15f8 in player_activity::finish (this=0xf74d9718, p=0xf74d91d4) at src/player_activity.cpp:235
#10 0x080e14e4 in player_activity::do_turn (this=0xf74d9718, p=0xf74d91d4) at src/player_activity.cpp:208
#11 0x081fb5e7 in game::process_activity (this=0xf7488008) at src/game.cpp:1589
#12 0x081f9b3c in game::do_turn (this=0xf7488008) at src/game.cpp:1405
#13 0x0864d18a in main (argc=0, argv=0xffceb418) at src/main.cpp:295

In English, code inside complete_craft() triggered drawing which in turn triggered an interruption check, which wiped the activity while it was still in-use, causing the crash. There are two fixes for this, the one I'm going to make is removing the access of activity after complete_craft() is called. The more complete fix is disentangling checking for interruptions from the drawing code, which needs to happen at some point because this is loopy, but not something I want to tackle right now.