Function error_tostring

library/LuaTools.cpp:534–556

static int DFHACK_EXCEPTION_META_TOKEN = 0;

static void error_tostring(lua_State *L, bool keep_old = false)
{
    lua_rawgetp(L, LUA_REGISTRYINDEX, &DFHACK_TOSTRING_TOKEN);
    if (keep_old)
        lua_pushvalue(L, -2);
    else
        lua_swap(L);

    bool ok = lua_pcall(L, 1, 1, 0) == LUA_OK;

    const char *msg = lua_tostring(L, -1);
    if (!msg)
    {
        msg = "tostring didn't return a string";
        ok = false;
    }

    if (!ok)
    {
        lua_pushfstring(L, "(invalid error: %s)", msg);
        lua_remove(L, -2);
    }
}

static void report_error(lua_State *L, color_ostream *out = NULL, bool pop = false)
{