(svn r28004) -Update from Eints:

[openttd.git] / src / settings.cpp

/* $Id$ */

/*
 * This file is part of OpenTTD.
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */

/**
 * @file settings.cpp
 * All actions handling saving and loading of the settings/configuration goes on in this file.
 * The file consists of three parts:
 * <ol>
 * <li>Parsing the configuration file (openttd.cfg). This is achieved with the ini_ functions which
 *     handle various types, such as normal 'key = value' pairs, lists and value combinations of
 *     lists, strings, integers, 'bit'-masks and element selections.
 * <li>Handle reading and writing to the setting-structures from inside the game either from
 *     the console for example or through the gui with CMD_ functions.
 * <li>Handle saving/loading of the PATS chunk inside the savegame.
 * </ol>
 * @see SettingDesc
 * @see SaveLoad
 */

#include "stdafx.h"
#include "currency.h"
#include "screenshot.h"
#include "network/network.h"
#include "network/network_func.h"
#include "settings_internal.h"
#include "command_func.h"
#include "console_func.h"
#include "pathfinder/pathfinder_type.h"
#include "genworld.h"
#include "train.h"
#include "news_func.h"
#include "window_func.h"
#include "sound_func.h"
#include "company_func.h"
#include "rev.h"
#ifdef WITH_FREETYPE
#include "fontcache.h"
#endif
#include "textbuf_gui.h"
#include "rail_gui.h"
#include "elrail_func.h"
#include "error.h"
#include "town.h"
#include "video/video_driver.hpp"
#include "sound/sound_driver.hpp"
#include "music/music_driver.hpp"
#include "blitter/factory.hpp"
#include "base_media_base.h"
#include "gamelog.h"
#include "settings_func.h"
#include "ini_type.h"
#include "ai/ai_config.hpp"
#include "ai/ai.hpp"
#include "game/game_config.hpp"
#include "game/game.hpp"
#include "ship.h"
#include "smallmap_gui.h"
#include "roadveh.h"
#include "fios.h"
#include "strings_func.h"

#include "void_map.h"
#include "station_base.h"

#include "table/strings.h"
#include "table/settings.h"

#include "safeguards.h"

ClientSettings _settings_client;
GameSettings _settings_game;     ///< Game settings of a running game or the scenario editor.
GameSettings _settings_newgame;  ///< Game settings for new games (updated from the intro screen).
VehicleDefaultSettings _old_vds; ///< Used for loading default vehicles settings from old savegames
char *_config_file; ///< Configuration file of OpenTTD

typedef std::list<ErrorMessageData> ErrorList;
static ErrorList _settings_error_list; ///< Errors while loading minimal settings.


typedef void SettingDescProc(IniFile *ini, const SettingDesc *desc, const char *grpname, void *object);
typedef void SettingDescProcList(IniFile *ini, const char *grpname, StringList *list);

static bool IsSignedVarMemType(VarType vt);

/**
 * Groups in openttd.cfg that are actually lists.
 */
static const char * const _list_group_names[] = {
        "bans",
        "newgrf",
        "servers",
        "server_bind_addresses",
        NULL
};

/**
 * Find the index value of a ONEofMANY type in a string separated by |
 * @param many full domain of values the ONEofMANY setting can have
 * @param one the current value of the setting for which a value needs found
 * @param onelen force calculation of the *one parameter
 * @return the integer index of the full-list, or -1 if not found
 */
static size_t LookupOneOfMany(const char *many, const char *one, size_t onelen = 0)
{
        const char *s;
        size_t idx;

        if (onelen == 0) onelen = strlen(one);

        /* check if it's an integer */
        if (*one >= '0' && *one <= '9') return strtoul(one, NULL, 0);

        idx = 0;
        for (;;) {
                /* find end of item */
                s = many;
                while (*s != '|' && *s != 0) s++;
                if ((size_t)(s - many) == onelen && !memcmp(one, many, onelen)) return idx;
                if (*s == 0) return (size_t)-1;
                many = s + 1;
                idx++;
        }
}

/**
 * Find the set-integer value MANYofMANY type in a string
 * @param many full domain of values the MANYofMANY setting can have
 * @param str the current string value of the setting, each individual
 * of separated by a whitespace,tab or | character
 * @return the 'fully' set integer, or -1 if a set is not found
 */
static size_t LookupManyOfMany(const char *many, const char *str)
{
        const char *s;
        size_t r;
        size_t res = 0;

        for (;;) {
                /* skip "whitespace" */
                while (*str == ' ' || *str == '\t' || *str == '|') str++;
                if (*str == 0) break;

                s = str;
                while (*s != 0 && *s != ' ' && *s != '\t' && *s != '|') s++;

                r = LookupOneOfMany(many, str, s - str);
                if (r == (size_t)-1) return r;

                SetBit(res, (uint8)r); // value found, set it
                if (*s == 0) break;
                str = s + 1;
        }
        return res;
}

/**
 * Parse an integerlist string and set each found value
 * @param p the string to be parsed. Each element in the list is separated by a
 * comma or a space character
 * @param items pointer to the integerlist-array that will be filled with values
 * @param maxitems the maximum number of elements the integerlist-array has
 * @return returns the number of items found, or -1 on an error
 */
static int ParseIntList(const char *p, int *items, int maxitems)
{
        int n = 0; // number of items read so far
        bool comma = false; // do we accept comma?

        while (*p != '\0') {
                switch (*p) {
                        case ',':
                                /* Do not accept multiple commas between numbers */
                                if (!comma) return -1;
                                comma = false;
                                FALLTHROUGH;

                        case ' ':
                                p++;
                                break;

                        default: {
                                if (n == maxitems) return -1; // we don't accept that many numbers
                                char *end;
                                long v = strtol(p, &end, 0);
                                if (p == end) return -1; // invalid character (not a number)
                                if (sizeof(int) < sizeof(long)) v = ClampToI32(v);
                                items[n++] = v;
                                p = end; // first non-number
                                comma = true; // we accept comma now
                                break;
                        }
                }
        }

        /* If we have read comma but no number after it, fail.
         * We have read comma when (n != 0) and comma is not allowed */
        if (n != 0 && !comma) return -1;

        return n;
}

/**
 * Load parsed string-values into an integer-array (intlist)
 * @param str the string that contains the values (and will be parsed)
 * @param array pointer to the integer-arrays that will be filled
 * @param nelems the number of elements the array holds. Maximum is 64 elements
 * @param type the type of elements the array holds (eg INT8, UINT16, etc.)
 * @return return true on success and false on error
 */
static bool LoadIntList(const char *str, void *array, int nelems, VarType type)
{
        int items[64];
        int i, nitems;

        if (str == NULL) {
                memset(items, 0, sizeof(items));
                nitems = nelems;
        } else {
                nitems = ParseIntList(str, items, lengthof(items));
                if (nitems != nelems) return false;
        }

        switch (type) {
                case SLE_VAR_BL:
                case SLE_VAR_I8:
                case SLE_VAR_U8:
                        for (i = 0; i != nitems; i++) ((byte*)array)[i] = items[i];
                        break;

                case SLE_VAR_I16:
                case SLE_VAR_U16:
                        for (i = 0; i != nitems; i++) ((uint16*)array)[i] = items[i];
                        break;

                case SLE_VAR_I32:
                case SLE_VAR_U32:
                        for (i = 0; i != nitems; i++) ((uint32*)array)[i] = items[i];
                        break;

                default: NOT_REACHED();
        }

        return true;
}

/**
 * Convert an integer-array (intlist) to a string representation. Each value
 * is separated by a comma or a space character
 * @param buf output buffer where the string-representation will be stored
 * @param last last item to write to in the output buffer
 * @param array pointer to the integer-arrays that is read from
 * @param nelems the number of elements the array holds.
 * @param type the type of elements the array holds (eg INT8, UINT16, etc.)
 */
static void MakeIntList(char *buf, const char *last, const void *array, int nelems, VarType type)
{
        int i, v = 0;
        const byte *p = (const byte *)array;

        for (i = 0; i != nelems; i++) {
                switch (type) {
                        case SLE_VAR_BL:
                        case SLE_VAR_I8:  v = *(const   int8 *)p; p += 1; break;
                        case SLE_VAR_U8:  v = *(const  uint8 *)p; p += 1; break;
                        case SLE_VAR_I16: v = *(const  int16 *)p; p += 2; break;
                        case SLE_VAR_U16: v = *(const uint16 *)p; p += 2; break;
                        case SLE_VAR_I32: v = *(const  int32 *)p; p += 4; break;
                        case SLE_VAR_U32: v = *(const uint32 *)p; p += 4; break;
                        default: NOT_REACHED();
                }
                buf += seprintf(buf, last, (i == 0) ? "%d" : ",%d", v);
        }
}

/**
 * Convert a ONEofMANY structure to a string representation.
 * @param buf output buffer where the string-representation will be stored
 * @param last last item to write to in the output buffer
 * @param many the full-domain string of possible values
 * @param id the value of the variable and whose string-representation must be found
 */
static void MakeOneOfMany(char *buf, const char *last, const char *many, int id)
{
        int orig_id = id;

        /* Look for the id'th element */
        while (--id >= 0) {
                for (; *many != '|'; many++) {
                        if (*many == '\0') { // not found
                                seprintf(buf, last, "%d", orig_id);
                                return;
                        }
                }
                many++; // pass the |-character
        }

        /* copy string until next item (|) or the end of the list if this is the last one */
        while (*many != '\0' && *many != '|' && buf < last) *buf++ = *many++;
        *buf = '\0';
}

/**
 * Convert a MANYofMANY structure to a string representation.
 * @param buf output buffer where the string-representation will be stored
 * @param last last item to write to in the output buffer
 * @param many the full-domain string of possible values
 * @param x the value of the variable and whose string-representation must
 *        be found in the bitmasked many string
 */
static void MakeManyOfMany(char *buf, const char *last, const char *many, uint32 x)
{
        const char *start;
        int i = 0;
        bool init = true;

        for (; x != 0; x >>= 1, i++) {
                start = many;
                while (*many != 0 && *many != '|') many++; // advance to the next element

                if (HasBit(x, 0)) { // item found, copy it
                        if (!init) buf += seprintf(buf, last, "|");
                        init = false;
                        if (start == many) {
                                buf += seprintf(buf, last, "%d", i);
                        } else {
                                memcpy(buf, start, many - start);
                                buf += many - start;
                        }
                }

                if (*many == '|') many++;
        }

        *buf = '\0';
}

/**
 * Convert a string representation (external) of a setting to the internal rep.
 * @param desc SettingDesc struct that holds all information about the variable
 * @param orig_str input string that will be parsed based on the type of desc
 * @return return the parsed value of the setting
 */
static const void *StringToVal(const SettingDescBase *desc, const char *orig_str)
{
        const char *str = orig_str == NULL ? "" : orig_str;

        switch (desc->cmd) {
                case SDT_NUMX: {
                        char *end;
                        size_t val = strtoul(str, &end, 0);
                        if (end == str) {
                                ErrorMessageData msg(STR_CONFIG_ERROR, STR_CONFIG_ERROR_INVALID_VALUE);
                                msg.SetDParamStr(0, str);
                                msg.SetDParamStr(1, desc->name);
                                _settings_error_list.push_back(msg);
                                return desc->def;
                        }
                        if (*end != '\0') {
                                ErrorMessageData msg(STR_CONFIG_ERROR, STR_CONFIG_ERROR_TRAILING_CHARACTERS);
                                msg.SetDParamStr(0, desc->name);
                                _settings_error_list.push_back(msg);
                        }
                        return (void*)val;
                }

                case SDT_ONEOFMANY: {
                        size_t r = LookupOneOfMany(desc->many, str);
                        /* if the first attempt of conversion from string to the appropriate value fails,
                         * look if we have defined a converter from old value to new value. */
                        if (r == (size_t)-1 && desc->proc_cnvt != NULL) r = desc->proc_cnvt(str);
                        if (r != (size_t)-1) return (void*)r; // and here goes converted value

                        ErrorMessageData msg(STR_CONFIG_ERROR, STR_CONFIG_ERROR_INVALID_VALUE);
                        msg.SetDParamStr(0, str);
                        msg.SetDParamStr(1, desc->name);
                        _settings_error_list.push_back(msg);
                        return desc->def;
                }

                case SDT_MANYOFMANY: {
                        size_t r = LookupManyOfMany(desc->many, str);
                        if (r != (size_t)-1) return (void*)r;
                        ErrorMessageData msg(STR_CONFIG_ERROR, STR_CONFIG_ERROR_INVALID_VALUE);
                        msg.SetDParamStr(0, str);
                        msg.SetDParamStr(1, desc->name);
                        _settings_error_list.push_back(msg);
                        return desc->def;
                }

                case SDT_BOOLX: {
                        if (strcmp(str, "true")  == 0 || strcmp(str, "on")  == 0 || strcmp(str, "1") == 0) return (void*)true;
                        if (strcmp(str, "false") == 0 || strcmp(str, "off") == 0 || strcmp(str, "0") == 0) return (void*)false;

                        ErrorMessageData msg(STR_CONFIG_ERROR, STR_CONFIG_ERROR_INVALID_VALUE);
                        msg.SetDParamStr(0, str);
                        msg.SetDParamStr(1, desc->name);
                        _settings_error_list.push_back(msg);
                        return desc->def;
                }

                case SDT_STRING: return orig_str;
                case SDT_INTLIST: return str;
                default: break;
        }

        return NULL;
}

/**
 * Set the value of a setting and if needed clamp the value to
 * the preset minimum and maximum.
 * @param ptr the variable itself
 * @param sd pointer to the 'information'-database of the variable
 * @param val signed long version of the new value
 * @pre SettingDesc is of type SDT_BOOLX, SDT_NUMX,
 * SDT_ONEOFMANY or SDT_MANYOFMANY. Other types are not supported as of now
 */
static void Write_ValidateSetting(void *ptr, const SettingDesc *sd, int32 val)
{
        const SettingDescBase *sdb = &sd->desc;

        if (sdb->cmd != SDT_BOOLX &&
                        sdb->cmd != SDT_NUMX &&
                        sdb->cmd != SDT_ONEOFMANY &&
                        sdb->cmd != SDT_MANYOFMANY) {
                return;
        }

        /* We cannot know the maximum value of a bitset variable, so just have faith */
        if (sdb->cmd != SDT_MANYOFMANY) {
                /* We need to take special care of the uint32 type as we receive from the function
                 * a signed integer. While here also bail out on 64-bit settings as those are not
                 * supported. Unsigned 8 and 16-bit variables are safe since they fit into a signed
                 * 32-bit variable
                 * TODO: Support 64-bit settings/variables */
                switch (GetVarMemType(sd->save.conv)) {
                        case SLE_VAR_NULL: return;
                        case SLE_VAR_BL:
                        case SLE_VAR_I8:
                        case SLE_VAR_U8:
                        case SLE_VAR_I16:
                        case SLE_VAR_U16:
                        case SLE_VAR_I32: {
                                /* Override the minimum value. No value below sdb->min, except special value 0 */
                                if (!(sdb->flags & SGF_0ISDISABLED) || val != 0) val = Clamp(val, sdb->min, sdb->max);
                                break;
                        }
                        case SLE_VAR_U32: {
                                /* Override the minimum value. No value below sdb->min, except special value 0 */
                                uint min = ((sdb->flags & SGF_0ISDISABLED) && (uint)val <= (uint)sdb->min) ? 0 : sdb->min;
                                WriteValue(ptr, SLE_VAR_U32, (int64)ClampU(val, min, sdb->max));
                                return;
                        }
                        case SLE_VAR_I64:
                        case SLE_VAR_U64:
                        default: NOT_REACHED();
                }
        }

        WriteValue(ptr, sd->save.conv, (int64)val);
}

/**
 * Load values from a group of an IniFile structure into the internal representation
 * @param ini pointer to IniFile structure that holds administrative information
 * @param sd pointer to SettingDesc structure whose internally pointed variables will
 *        be given values
 * @param grpname the group of the IniFile to search in for the new values
 * @param object pointer to the object been loaded
 */
static void IniLoadSettings(IniFile *ini, const SettingDesc *sd, const char *grpname, void *object)
{
        IniGroup *group;
        IniGroup *group_def = ini->GetGroup(grpname);
        IniItem *item;
        const void *p;
        void *ptr;
        const char *s;

        for (; sd->save.cmd != SL_END; sd++) {
                const SettingDescBase *sdb = &sd->desc;
                const SaveLoad        *sld = &sd->save;

                if (!SlIsObjectCurrentlyValid(sld->version_from, sld->version_to)) continue;

                /* For settings.xx.yy load the settings from [xx] yy = ? */
                s = strchr(sdb->name, '.');
                if (s != NULL) {
                        group = ini->GetGroup(sdb->name, s - sdb->name);
                        s++;
                } else {
                        s = sdb->name;
                        group = group_def;
                }

                item = group->GetItem(s, false);
                if (item == NULL && group != group_def) {
                        /* For settings.xx.yy load the settings from [settingss] yy = ? in case the previous
                         * did not exist (e.g. loading old config files with a [settings] section */
                        item = group_def->GetItem(s, false);
                }
                if (item == NULL) {
                        /* For settings.xx.zz.yy load the settings from [zz] yy = ? in case the previous
                         * did not exist (e.g. loading old config files with a [yapf] section */
                        const char *sc = strchr(s, '.');
                        if (sc != NULL) item = ini->GetGroup(s, sc - s)->GetItem(sc + 1, false);
                }

                p = (item == NULL) ? sdb->def : StringToVal(sdb, item->value);
                ptr = GetVariableAddress(object, sld);

                switch (sdb->cmd) {
                        case SDT_BOOLX: // All four are various types of (integer) numbers
                        case SDT_NUMX:
                        case SDT_ONEOFMANY:
                        case SDT_MANYOFMANY:
                                Write_ValidateSetting(ptr, sd, (int32)(size_t)p);
                                break;

                        case SDT_STRING:
                                switch (GetVarMemType(sld->conv)) {
                                        case SLE_VAR_STRB:
                                        case SLE_VAR_STRBQ:
                                                if (p != NULL) strecpy((char*)ptr, (const char*)p, (char*)ptr + sld->length - 1);
                                                break;

                                        case SLE_VAR_STR:
                                        case SLE_VAR_STRQ:
                                                free(*(char**)ptr);
                                                *(char**)ptr = p == NULL ? NULL : stredup((const char*)p);
                                                break;

                                        case SLE_VAR_CHAR: if (p != NULL) *(char *)ptr = *(const char *)p; break;

                                        default: NOT_REACHED();
                                }
                                break;

                        case SDT_INTLIST: {
                                if (!LoadIntList((const char*)p, ptr, sld->length, GetVarMemType(sld->conv))) {
                                        ErrorMessageData msg(STR_CONFIG_ERROR, STR_CONFIG_ERROR_ARRAY);
                                        msg.SetDParamStr(0, sdb->name);
                                        _settings_error_list.push_back(msg);

                                        /* Use default */
                                        LoadIntList((const char*)sdb->def, ptr, sld->length, GetVarMemType(sld->conv));
                                } else if (sd->desc.proc_cnvt != NULL) {
                                        sd->desc.proc_cnvt((const char*)p);
                                }
                                break;
                        }
                        default: NOT_REACHED();
                }
        }
}

/**
 * Save the values of settings to the inifile.
 * @param ini pointer to IniFile structure
 * @param sd read-only SettingDesc structure which contains the unmodified,
 *        loaded values of the configuration file and various information about it
 * @param grpname holds the name of the group (eg. [network]) where these will be saved
 * @param object pointer to the object been saved
 * The function works as follows: for each item in the SettingDesc structure we
 * have a look if the value has changed since we started the game (the original
 * values are reloaded when saving). If settings indeed have changed, we get
 * these and save them.
 */
static void IniSaveSettings(IniFile *ini, const SettingDesc *sd, const char *grpname, void *object)
{
        IniGroup *group_def = NULL, *group;
        IniItem *item;
        char buf[512];
        const char *s;
        void *ptr;

        for (; sd->save.cmd != SL_END; sd++) {
                const SettingDescBase *sdb = &sd->desc;
                const SaveLoad        *sld = &sd->save;

                /* If the setting is not saved to the configuration
                 * file, just continue with the next setting */
                if (!SlIsObjectCurrentlyValid(sld->version_from, sld->version_to)) continue;
                if (sld->conv & SLF_NOT_IN_CONFIG) continue;

                /* XXX - wtf is this?? (group override?) */
                s = strchr(sdb->name, '.');
                if (s != NULL) {
                        group = ini->GetGroup(sdb->name, s - sdb->name);
                        s++;
                } else {
                        if (group_def == NULL) group_def = ini->GetGroup(grpname);
                        s = sdb->name;
                        group = group_def;
                }

                item = group->GetItem(s, true);
                ptr = GetVariableAddress(object, sld);

                if (item->value != NULL) {
                        /* check if the value is the same as the old value */
                        const void *p = StringToVal(sdb, item->value);

                        /* The main type of a variable/setting is in bytes 8-15
                         * The subtype (what kind of numbers do we have there) is in 0-7 */
                        switch (sdb->cmd) {
                                case SDT_BOOLX:
                                case SDT_NUMX:
                                case SDT_ONEOFMANY:
                                case SDT_MANYOFMANY:
                                        switch (GetVarMemType(sld->conv)) {
                                                case SLE_VAR_BL:
                                                        if (*(bool*)ptr == (p != NULL)) continue;
                                                        break;

                                                case SLE_VAR_I8:
                                                case SLE_VAR_U8:
                                                        if (*(byte*)ptr == (byte)(size_t)p) continue;
                                                        break;

                                                case SLE_VAR_I16:
                                                case SLE_VAR_U16:
                                                        if (*(uint16*)ptr == (uint16)(size_t)p) continue;
                                                        break;

                                                case SLE_VAR_I32:
                                                case SLE_VAR_U32:
                                                        if (*(uint32*)ptr == (uint32)(size_t)p) continue;
                                                        break;

                                                default: NOT_REACHED();
                                        }
                                        break;

                                default: break; // Assume the other types are always changed
                        }
                }

                /* Value has changed, get the new value and put it into a buffer */
                switch (sdb->cmd) {
                        case SDT_BOOLX:
                        case SDT_NUMX:
                        case SDT_ONEOFMANY:
                        case SDT_MANYOFMANY: {
                                uint32 i = (uint32)ReadValue(ptr, sld->conv);

                                switch (sdb->cmd) {
                                        case SDT_BOOLX:      strecpy(buf, (i != 0) ? "true" : "false", lastof(buf)); break;
                                        case SDT_NUMX:       seprintf(buf, lastof(buf), IsSignedVarMemType(sld->conv) ? "%d" : "%u", i); break;
                                        case SDT_ONEOFMANY:  MakeOneOfMany(buf, lastof(buf), sdb->many, i); break;
                                        case SDT_MANYOFMANY: MakeManyOfMany(buf, lastof(buf), sdb->many, i); break;
                                        default: NOT_REACHED();
                                }
                                break;
                        }

                        case SDT_STRING:
                                switch (GetVarMemType(sld->conv)) {
                                        case SLE_VAR_STRB: strecpy(buf, (char*)ptr, lastof(buf)); break;
                                        case SLE_VAR_STRBQ:seprintf(buf, lastof(buf), "\"%s\"", (char*)ptr); break;
                                        case SLE_VAR_STR:  strecpy(buf, *(char**)ptr, lastof(buf)); break;

                                        case SLE_VAR_STRQ:
                                                if (*(char**)ptr == NULL) {
                                                        buf[0] = '\0';
                                                } else {
                                                        seprintf(buf, lastof(buf), "\"%s\"", *(char**)ptr);
                                                }
                                                break;

                                        case SLE_VAR_CHAR: buf[0] = *(char*)ptr; buf[1] = '\0'; break;
                                        default: NOT_REACHED();
                                }
                                break;

                        case SDT_INTLIST:
                                MakeIntList(buf, lastof(buf), ptr, sld->length, GetVarMemType(sld->conv));
                                break;

                        default: NOT_REACHED();
                }

                /* The value is different, that means we have to write it to the ini */
                free(item->value);
                item->value = stredup(buf);
        }
}

/**
 * Loads all items from a 'grpname' section into a list
 * The list parameter can be a NULL pointer, in this case nothing will be
 * saved and a callback function should be defined that will take over the
 * list-handling and store the data itself somewhere.
 * @param ini IniFile handle to the ini file with the source data
 * @param grpname character string identifying the section-header of the ini file that will be parsed
 * @param list new list with entries of the given section
 */
static void IniLoadSettingList(IniFile *ini, const char *grpname, StringList *list)
{
        IniGroup *group = ini->GetGroup(grpname);

        if (group == NULL || list == NULL) return;

        list->Clear();

        for (const IniItem *item = group->item; item != NULL; item = item->next) {
                if (item->name != NULL) *list->Append() = stredup(item->name);
        }
}

/**
 * Saves all items from a list into the 'grpname' section
 * The list parameter can be a NULL pointer, in this case a callback function
 * should be defined that will provide the source data to be saved.
 * @param ini IniFile handle to the ini file where the destination data is saved
 * @param grpname character string identifying the section-header of the ini file
 * @param list pointer to an string(pointer) array that will be used as the
 *             source to be saved into the relevant ini section
 */
static void IniSaveSettingList(IniFile *ini, const char *grpname, StringList *list)
{
        IniGroup *group = ini->GetGroup(grpname);

        if (group == NULL || list == NULL) return;
        group->Clear();

        for (char **iter = list->Begin(); iter != list->End(); iter++) {
                group->GetItem(*iter, true)->SetValue("");
        }
}

/**
 * Load a WindowDesc from config.
 * @param ini IniFile handle to the ini file with the source data
 * @param grpname character string identifying the section-header of the ini file that will be parsed
 * @param desc Destination WindowDesc
 */
void IniLoadWindowSettings(IniFile *ini, const char *grpname, void *desc)
{
        IniLoadSettings(ini, _window_settings, grpname, desc);
}

/**
 * Save a WindowDesc to config.
 * @param ini IniFile handle to the ini file where the destination data is saved
 * @param grpname character string identifying the section-header of the ini file
 * @param desc Source WindowDesc
 */
void IniSaveWindowSettings(IniFile *ini, const char *grpname, void *desc)
{
        IniSaveSettings(ini, _window_settings, grpname, desc);
}

/**
 * Check whether the setting is editable in the current gamemode.
 * @param do_command true if this is about checking a command from the server.
 * @return true if editable.
 */
bool SettingDesc::IsEditable(bool do_command) const
{
        if (!do_command && !(this->save.conv & SLF_NO_NETWORK_SYNC) && _networking && !_network_server && !(this->desc.flags & SGF_PER_COMPANY)) return false;
        if ((this->desc.flags & SGF_NETWORK_ONLY) && !_networking && _game_mode != GM_MENU) return false;
        if ((this->desc.flags & SGF_NO_NETWORK) && _networking) return false;
        if ((this->desc.flags & SGF_NEWGAME_ONLY) &&
                        (_game_mode == GM_NORMAL ||
                        (_game_mode == GM_EDITOR && !(this->desc.flags & SGF_SCENEDIT_TOO)))) return false;
        return true;
}

/**
 * Return the type of the setting.
 * @return type of setting
 */
SettingType SettingDesc::GetType() const
{
        if (this->desc.flags & SGF_PER_COMPANY) return ST_COMPANY;
        return (this->save.conv & SLF_NOT_IN_SAVE) ? ST_CLIENT : ST_GAME;
}

/* Begin - Callback Functions for the various settings. */

/** Reposition the main toolbar as the setting changed. */
static bool v_PositionMainToolbar(int32 p1)
{
        if (_game_mode != GM_MENU) PositionMainToolbar(NULL);
        return true;
}

/** Reposition the statusbar as the setting changed. */
static bool v_PositionStatusbar(int32 p1)
{
        if (_game_mode != GM_MENU) {
                PositionStatusbar(NULL);
                PositionNewsMessage(NULL);
                PositionNetworkChatWindow(NULL);
        }
        return true;
}

static bool PopulationInLabelActive(int32 p1)
{
        UpdateAllTownVirtCoords();
        return true;
}

static bool RedrawScreen(int32 p1)
{
        MarkWholeScreenDirty();
        return true;
}

/**
 * Redraw the smallmap after a colour scheme change.
 * @param p1 Callback parameter.
 * @return Always true.
 */
static bool RedrawSmallmap(int32 p1)
{
        BuildLandLegend();
        BuildOwnerLegend();
        SetWindowClassesDirty(WC_SMALLMAP);
        return true;
}

static bool InvalidateDetailsWindow(int32 p1)
{
        SetWindowClassesDirty(WC_VEHICLE_DETAILS);
        return true;
}

static bool StationSpreadChanged(int32 p1)
{
        InvalidateWindowData(WC_SELECT_STATION, 0);
        InvalidateWindowData(WC_BUILD_STATION, 0);
        return true;
}

static bool InvalidateBuildIndustryWindow(int32 p1)
{
        InvalidateWindowData(WC_BUILD_INDUSTRY, 0);
        return true;
}

static bool CloseSignalGUI(int32 p1)
{
        if (p1 == 0) {
                DeleteWindowByClass(WC_BUILD_SIGNAL);
        }
        return true;
}

static bool InvalidateTownViewWindow(int32 p1)
{
        InvalidateWindowClassesData(WC_TOWN_VIEW, p1);
        return true;
}

static bool DeleteSelectStationWindow(int32 p1)
{
        DeleteWindowById(WC_SELECT_STATION, 0);
        return true;
}

static bool UpdateConsists(int32 p1)
{
        Train *t;
        FOR_ALL_TRAINS(t) {
                /* Update the consist of all trains so the maximum speed is set correctly. */
                if (t->IsFrontEngine() || t->IsFreeWagon()) t->ConsistChanged(CCF_TRACK);
        }
        InvalidateWindowClassesData(WC_BUILD_VEHICLE, 0);
        return true;
}

/* Check service intervals of vehicles, p1 is value of % or day based servicing */
static bool CheckInterval(int32 p1)
{
        bool update_vehicles;
        VehicleDefaultSettings *vds;
        if (_game_mode == GM_MENU || !Company::IsValidID(_current_company)) {
                vds = &_settings_client.company.vehicle;
                update_vehicles = false;
        } else {
                vds = &Company::Get(_current_company)->settings.vehicle;
                update_vehicles = true;
        }

        if (p1 != 0) {
                vds->servint_trains   = 50;
                vds->servint_roadveh  = 50;
                vds->servint_aircraft = 50;
                vds->servint_ships    = 50;
        } else {
                vds->servint_trains   = 150;
                vds->servint_roadveh  = 150;
                vds->servint_aircraft = 100;
                vds->servint_ships    = 360;
        }

        if (update_vehicles) {
                const Company *c = Company::Get(_current_company);
                Vehicle *v;
                FOR_ALL_VEHICLES(v) {
                        if (v->owner == _current_company && v->IsPrimaryVehicle() && !v->ServiceIntervalIsCustom()) {
                                v->SetServiceInterval(CompanyServiceInterval(c, v->type));
                                v->SetServiceIntervalIsPercent(p1 != 0);
                        }
                }
        }

        InvalidateDetailsWindow(0);

        return true;
}

static bool UpdateInterval(VehicleType type, int32 p1)
{
        bool update_vehicles;
        VehicleDefaultSettings *vds;
        if (_game_mode == GM_MENU || !Company::IsValidID(_current_company)) {
                vds = &_settings_client.company.vehicle;
                update_vehicles = false;
        } else {
                vds = &Company::Get(_current_company)->settings.vehicle;
                update_vehicles = true;
        }

        /* Test if the interval is valid */
        uint16 interval = GetServiceIntervalClamped(p1, vds->servint_ispercent);
        if (interval != p1) return false;

        if (update_vehicles) {
                Vehicle *v;
                FOR_ALL_VEHICLES(v) {
                        if (v->owner == _current_company && v->type == type && v->IsPrimaryVehicle() && !v->ServiceIntervalIsCustom()) {
                                v->SetServiceInterval(p1);
                        }
                }
        }

        InvalidateDetailsWindow(0);

        return true;
}

static bool UpdateIntervalTrains(int32 p1)
{
        return UpdateInterval(VEH_TRAIN, p1);
}

static bool UpdateIntervalRoadVeh(int32 p1)
{
        return UpdateInterval(VEH_ROAD, p1);
}

static bool UpdateIntervalShips(int32 p1)
{
        return UpdateInterval(VEH_SHIP, p1);
}

static bool UpdateIntervalAircraft(int32 p1)
{
        return UpdateInterval(VEH_AIRCRAFT, p1);
}

static bool TrainAccelerationModelChanged(int32 p1)
{
        Train *t;
        FOR_ALL_TRAINS(t) {
                if (t->IsFrontEngine()) {
                        t->tcache.cached_max_curve_speed = t->GetCurveSpeedLimit();
                        t->UpdateAcceleration();
                }
        }

        /* These windows show acceleration values only when realistic acceleration is on. They must be redrawn after a setting change. */
        SetWindowClassesDirty(WC_ENGINE_PREVIEW);
        InvalidateWindowClassesData(WC_BUILD_VEHICLE, 0);
        SetWindowClassesDirty(WC_VEHICLE_DETAILS);

        return true;
}

/**
 * This function updates the train acceleration cache after a steepness change.
 * @param p1 Callback parameter.
 * @return Always true.
 */
static bool TrainSlopeSteepnessChanged(int32 p1)
{
        Train *t;
        FOR_ALL_TRAINS(t) {
                if (t->IsFrontEngine()) t->CargoChanged();
        }

        return true;
}

/**
 * This function updates realistic acceleration caches when the setting "Road vehicle acceleration model" is set.
 * @param p1 Callback parameter
 * @return Always true
 */
static bool RoadVehAccelerationModelChanged(int32 p1)
{
        if (_settings_game.vehicle.roadveh_acceleration_model != AM_ORIGINAL) {
                RoadVehicle *rv;
                FOR_ALL_ROADVEHICLES(rv) {
                        if (rv->IsFrontEngine()) {
                                rv->CargoChanged();
                        }
                }
        }

        /* These windows show acceleration values only when realistic acceleration is on. They must be redrawn after a setting change. */
        SetWindowClassesDirty(WC_ENGINE_PREVIEW);
        InvalidateWindowClassesData(WC_BUILD_VEHICLE, 0);
        SetWindowClassesDirty(WC_VEHICLE_DETAILS);

        return true;
}

/**
 * This function updates the road vehicle acceleration cache after a steepness change.
 * @param p1 Callback parameter.
 * @return Always true.
 */
static bool RoadVehSlopeSteepnessChanged(int32 p1)
{
        RoadVehicle *rv;
        FOR_ALL_ROADVEHICLES(rv) {
                if (rv->IsFrontEngine()) rv->CargoChanged();
        }

        return true;
}

static bool DragSignalsDensityChanged(int32)
{
        InvalidateWindowData(WC_BUILD_SIGNAL, 0);

        return true;
}

static bool TownFoundingChanged(int32 p1)
{
        if (_game_mode != GM_EDITOR && _settings_game.economy.found_town == TF_FORBIDDEN) {
                DeleteWindowById(WC_FOUND_TOWN, 0);
                return true;
        }
        InvalidateWindowData(WC_FOUND_TOWN, 0);
        return true;
}

static bool InvalidateVehTimetableWindow(int32 p1)
{
        InvalidateWindowClassesData(WC_VEHICLE_TIMETABLE, VIWD_MODIFY_ORDERS);
        return true;
}

static bool ZoomMinMaxChanged(int32 p1)
{
        extern void ConstrainAllViewportsZoom();
        ConstrainAllViewportsZoom();
        GfxClearSpriteCache();
        if (_settings_client.gui.zoom_min > _gui_zoom) {
                /* Restrict GUI zoom if it is no longer available. */
                _gui_zoom = _settings_client.gui.zoom_min;
                UpdateCursorSize();
                LoadStringWidthTable();
        }
        return true;
}

/**
 * Update any possible saveload window and delete any newgrf dialogue as
 * its widget parts might change. Reinit all windows as it allows access to the
 * newgrf debug button.
 * @param p1 unused.
 * @return Always true.
 */
static bool InvalidateNewGRFChangeWindows(int32 p1)
{
        InvalidateWindowClassesData(WC_SAVELOAD);
        DeleteWindowByClass(WC_GAME_OPTIONS);
        ReInitAllWindows();
        return true;
}

static bool InvalidateCompanyLiveryWindow(int32 p1)
{
        InvalidateWindowClassesData(WC_COMPANY_COLOUR);
        return RedrawScreen(p1);
}

static bool InvalidateIndustryViewWindow(int32 p1)
{
        InvalidateWindowClassesData(WC_INDUSTRY_VIEW);
        return true;
}

static bool InvalidateAISettingsWindow(int32 p1)
{
        InvalidateWindowClassesData(WC_AI_SETTINGS);
        return true;
}

/**
 * Update the town authority window after a town authority setting change.
 * @param p1 Unused.
 * @return Always true.
 */
static bool RedrawTownAuthority(int32 p1)
{
        SetWindowClassesDirty(WC_TOWN_AUTHORITY);
        return true;
}

/**
 * Invalidate the company infrastructure details window after a infrastructure maintenance setting change.
 * @param p1 Unused.
 * @return Always true.
 */
static bool InvalidateCompanyInfrastructureWindow(int32 p1)
{
        InvalidateWindowClassesData(WC_COMPANY_INFRASTRUCTURE);
        return true;
}

/**
 * Invalidate the company details window after the shares setting changed.
 * @param p1 Unused.
 * @return Always true.
 */
static bool InvalidateCompanyWindow(int32 p1)
{
        InvalidateWindowClassesData(WC_COMPANY);
        return true;
}

/** Checks if any settings are set to incorrect values, and sets them to correct values in that case. */
static void ValidateSettings()
{
        /* Do not allow a custom sea level with the original land generator. */
        if (_settings_newgame.game_creation.land_generator == LG_ORIGINAL &&
                        _settings_newgame.difficulty.quantity_sea_lakes == CUSTOM_SEA_LEVEL_NUMBER_DIFFICULTY) {
                _settings_newgame.difficulty.quantity_sea_lakes = CUSTOM_SEA_LEVEL_MIN_PERCENTAGE;
        }
}

static bool DifficultyNoiseChange(int32 i)
{
        if (_game_mode == GM_NORMAL) {
                UpdateAirportsNoise();
                if (_settings_game.economy.station_noise_level) {
                        InvalidateWindowClassesData(WC_TOWN_VIEW, 0);
                }
        }

        return true;
}

static bool MaxNoAIsChange(int32 i)
{
        if (GetGameSettings().difficulty.max_no_competitors != 0 &&
                        AI::GetInfoList()->size() == 0 &&
                        (!_networking || _network_server)) {
                ShowErrorMessage(STR_WARNING_NO_SUITABLE_AI, INVALID_STRING_ID, WL_CRITICAL);
        }

        return true;
}

/**
 * Check whether the road side may be changed.
 * @param p1 unused
 * @return true if the road side may be changed.
 */
static bool CheckRoadSide(int p1)
{
        extern bool RoadVehiclesAreBuilt();
        return _game_mode == GM_MENU || !RoadVehiclesAreBuilt();
}

/**
 * Conversion callback for _gameopt_settings_game.landscape
 * It converts (or try) between old values and the new ones,
 * without losing initial setting of the user
 * @param value that was read from config file
 * @return the "hopefully" converted value
 */
static size_t ConvertLandscape(const char *value)
{
        /* try with the old values */
        return LookupOneOfMany("normal|hilly|desert|candy", value);
}

static bool CheckFreeformEdges(int32 p1)
{
        if (_game_mode == GM_MENU) return true;
        if (p1 != 0) {
                Ship *s;
                FOR_ALL_SHIPS(s) {
                        /* Check if there is a ship on the northern border. */
                        if (TileX(s->tile) == 0 || TileY(s->tile) == 0) {
                                ShowErrorMessage(STR_CONFIG_SETTING_EDGES_NOT_EMPTY, INVALID_STRING_ID, WL_ERROR);
                                return false;
                        }
                }
                BaseStation *st;
                FOR_ALL_BASE_STATIONS(st) {
                        /* Check if there is a non-deleted buoy on the northern border. */
                        if (st->IsInUse() && (TileX(st->xy) == 0 || TileY(st->xy) == 0)) {
                                ShowErrorMessage(STR_CONFIG_SETTING_EDGES_NOT_EMPTY, INVALID_STRING_ID, WL_ERROR);
                                return false;
                        }
                }
                for (uint i = 0; i < MapSizeX(); i++) MakeVoid(TileXY(i, 0));
                for (uint i = 0; i < MapSizeY(); i++) MakeVoid(TileXY(0, i));
        } else {
                for (uint i = 0; i < MapMaxX(); i++) {
                        if (TileHeight(TileXY(i, 1)) != 0) {
                                ShowErrorMessage(STR_CONFIG_SETTING_EDGES_NOT_WATER, INVALID_STRING_ID, WL_ERROR);
                                return false;
                        }
                }
                for (uint i = 1; i < MapMaxX(); i++) {
                        if (!IsTileType(TileXY(i, MapMaxY() - 1), MP_WATER) || TileHeight(TileXY(1, MapMaxY())) != 0) {
                                ShowErrorMessage(STR_CONFIG_SETTING_EDGES_NOT_WATER, INVALID_STRING_ID, WL_ERROR);
                                return false;
                        }
                }
                for (uint i = 0; i < MapMaxY(); i++) {
                        if (TileHeight(TileXY(1, i)) != 0) {
                                ShowErrorMessage(STR_CONFIG_SETTING_EDGES_NOT_WATER, INVALID_STRING_ID, WL_ERROR);
                                return false;
                        }
                }
                for (uint i = 1; i < MapMaxY(); i++) {
                        if (!IsTileType(TileXY(MapMaxX() - 1, i), MP_WATER) || TileHeight(TileXY(MapMaxX(), i)) != 0) {
                                ShowErrorMessage(STR_CONFIG_SETTING_EDGES_NOT_WATER, INVALID_STRING_ID, WL_ERROR);
                                return false;
                        }
                }
                /* Make tiles at the border water again. */
                for (uint i = 0; i < MapMaxX(); i++) {
                        SetTileHeight(TileXY(i, 0), 0);
                        SetTileType(TileXY(i, 0), MP_WATER);
                }
                for (uint i = 0; i < MapMaxY(); i++) {
                        SetTileHeight(TileXY(0, i), 0);
                        SetTileType(TileXY(0, i), MP_WATER);
                }
        }
        MarkWholeScreenDirty();
        return true;
}

/**
 * Changing the setting "allow multiple NewGRF sets" is not allowed
 * if there are vehicles.
 */
static bool ChangeDynamicEngines(int32 p1)
{
        if (_game_mode == GM_MENU) return true;

        if (!EngineOverrideManager::ResetToCurrentNewGRFConfig()) {
                ShowErrorMessage(STR_CONFIG_SETTING_DYNAMIC_ENGINES_EXISTING_VEHICLES, INVALID_STRING_ID, WL_ERROR);
                return false;
        }

        return true;
}

static bool ChangeMaxHeightLevel(int32 p1)
{
        if (_game_mode == GM_NORMAL) return false;
        if (_game_mode != GM_EDITOR) return true;

        /* Check if at least one mountain on the map is higher than the new value.
         * If yes, disallow the change. */
        for (TileIndex t = 0; t < MapSize(); t++) {
                if ((int32)TileHeight(t) > p1) {
                        ShowErrorMessage(STR_CONFIG_SETTING_TOO_HIGH_MOUNTAIN, INVALID_STRING_ID, WL_ERROR);
                        /* Return old, unchanged value */
                        return false;
                }
        }

        /* The smallmap uses an index from heightlevels to colours. Trigger rebuilding it. */
        InvalidateWindowClassesData(WC_SMALLMAP, 2);

        return true;
}

static bool StationCatchmentChanged(int32 p1)
{
        Station::RecomputeIndustriesNearForAll();
        return true;
}

static bool MaxVehiclesChanged(int32 p1)
{
        InvalidateWindowClassesData(WC_BUILD_TOOLBAR);
        MarkWholeScreenDirty();
        return true;
}


#ifdef ENABLE_NETWORK

static bool UpdateClientName(int32 p1)
{
        NetworkUpdateClientName();
        return true;
}

static bool UpdateServerPassword(int32 p1)
{
        if (strcmp(_settings_client.network.server_password, "*") == 0) {
                _settings_client.network.server_password[0] = '\0';
        }

        return true;
}

static bool UpdateRconPassword(int32 p1)
{
        if (strcmp(_settings_client.network.rcon_password, "*") == 0) {
                _settings_client.network.rcon_password[0] = '\0';
        }

        return true;
}

static bool UpdateClientConfigValues(int32 p1)
{
        if (_network_server) NetworkServerSendConfigUpdate();

        return true;
}

#endif /* ENABLE_NETWORK */


/* End - Callback Functions */

/**
 * Prepare for reading and old diff_custom by zero-ing the memory.
 */
static void PrepareOldDiffCustom()
{
        memset(_old_diff_custom, 0, sizeof(_old_diff_custom));
}

/**
 * Reading of the old diff_custom array and transforming it to the new format.
 * @param savegame is it read from the config or savegame. In the latter case
 *                 we are sure there is an array; in the former case we have
 *                 to check that.
 */
static void HandleOldDiffCustom(bool savegame)
{
        uint options_to_load = GAME_DIFFICULTY_NUM - ((savegame && IsSavegameVersionBefore(4)) ? 1 : 0);

        if (!savegame) {
                /* If we did read to old_diff_custom, then at least one value must be non 0. */
                bool old_diff_custom_used = false;
                for (uint i = 0; i < options_to_load && !old_diff_custom_used; i++) {
                        old_diff_custom_used = (_old_diff_custom[i] != 0);
                }

                if (!old_diff_custom_used) return;
        }

        for (uint i = 0; i < options_to_load; i++) {
                const SettingDesc *sd = &_settings[i];
                /* Skip deprecated options */
                if (!SlIsObjectCurrentlyValid(sd->save.version_from, sd->save.version_to)) continue;
                void *var = GetVariableAddress(savegame ? &_settings_game : &_settings_newgame, &sd->save);
                Write_ValidateSetting(var, sd, (int32)((i == 4 ? 1000 : 1) * _old_diff_custom[i]));
        }
}

static void AILoadConfig(IniFile *ini, const char *grpname)
{
        IniGroup *group = ini->GetGroup(grpname);
        IniItem *item;

        /* Clean any configured AI */
        for (CompanyID c = COMPANY_FIRST; c < MAX_COMPANIES; c++) {
                AIConfig::GetConfig(c, AIConfig::SSS_FORCE_NEWGAME)->Change(NULL);
        }

        /* If no group exists, return */
        if (group == NULL) return;

        CompanyID c = COMPANY_FIRST;
        for (item = group->item; c < MAX_COMPANIES && item != NULL; c++, item = item->next) {
                AIConfig *config = AIConfig::GetConfig(c, AIConfig::SSS_FORCE_NEWGAME);

                config->Change(item->name);
                if (!config->HasScript()) {
                        if (strcmp(item->name, "none") != 0) {
                                DEBUG(script, 0, "The AI by the name '%s' was no longer found, and removed from the list.", item->name);
                                continue;
                        }
                }
                if (item->value != NULL) config->StringToSettings(item->value);
        }
}

static void GameLoadConfig(IniFile *ini, const char *grpname)
{
        IniGroup *group = ini->GetGroup(grpname);
        IniItem *item;

        /* Clean any configured GameScript */
        GameConfig::GetConfig(GameConfig::SSS_FORCE_NEWGAME)->Change(NULL);

        /* If no group exists, return */
        if (group == NULL) return;

        item = group->item;
        if (item == NULL) return;

        GameConfig *config = GameConfig::GetConfig(AIConfig::SSS_FORCE_NEWGAME);

        config->Change(item->name);
        if (!config->HasScript()) {
                if (strcmp(item->name, "none") != 0) {
                        DEBUG(script, 0, "The GameScript by the name '%s' was no longer found, and removed from the list.", item->name);
                        return;
                }
        }
        if (item->value != NULL) config->StringToSettings(item->value);
}

/**
 * Convert a character to a hex nibble value, or \c -1 otherwise.
 * @param c Character to convert.
 * @return Hex value of the character, or \c -1 if not a hex digit.
 */
static int DecodeHexNibble(char c)
{
        if (c >= '0' && c <= '9') return c - '0';
        if (c >= 'A' && c <= 'F') return c + 10 - 'A';
        if (c >= 'a' && c <= 'f') return c + 10 - 'a';
        return -1;
}

/**
 * Parse a sequence of characters (supposedly hex digits) into a sequence of bytes.
 * After the hex number should be a \c '|' character.
 * @param pos First character to convert.
 * @param dest [out] Output byte array to write the bytes.
 * @param dest_size Number of bytes in \a dest.
 * @return Whether reading was successful.
 */
static bool DecodeHexText(char *pos, uint8 *dest, size_t dest_size)
{
        while (dest_size > 0) {
                int hi = DecodeHexNibble(pos[0]);
                int lo = (hi >= 0) ? DecodeHexNibble(pos[1]) : -1;
                if (lo < 0) return false;
                *dest++ = (hi << 4) | lo;
                pos += 2;
                dest_size--;
        }
        return *pos == '|';
}

/**
 * Load a GRF configuration
 * @param ini       The configuration to read from.
 * @param grpname   Group name containing the configuration of the GRF.
 * @param is_static GRF is static.
 */
static GRFConfig *GRFLoadConfig(IniFile *ini, const char *grpname, bool is_static)
{
        IniGroup *group = ini->GetGroup(grpname);
        IniItem *item;
        GRFConfig *first = NULL;
        GRFConfig **curr = &first;

        if (group == NULL) return NULL;

        for (item = group->item; item != NULL; item = item->next) {
                GRFConfig *c = NULL;

                uint8 grfid_buf[4], md5sum[16];
                char *filename = item->name;
                bool has_grfid = false;
                bool has_md5sum = false;

                /* Try reading "<grfid>|" and on success, "<md5sum>|". */
                has_grfid = DecodeHexText(filename, grfid_buf, lengthof(grfid_buf));
                if (has_grfid) {
                        filename += 1 + 2 * lengthof(grfid_buf);
                        has_md5sum = DecodeHexText(filename, md5sum, lengthof(md5sum));
                        if (has_md5sum) filename += 1 + 2 * lengthof(md5sum);

                        uint32 grfid = grfid_buf[0] | (grfid_buf[1] << 8) | (grfid_buf[2] << 16) | (grfid_buf[3] << 24);
                        if (has_md5sum) {
                                const GRFConfig *s = FindGRFConfig(grfid, FGCM_EXACT, md5sum);
                                if (s != NULL) c = new GRFConfig(*s);
                        }
                        if (c == NULL && !FioCheckFileExists(filename, NEWGRF_DIR)) {
                                const GRFConfig *s = FindGRFConfig(grfid, FGCM_NEWEST_VALID);
                                if (s != NULL) c = new GRFConfig(*s);
                        }
                }
                if (c == NULL) c = new GRFConfig(filename);

                /* Parse parameters */
                if (!StrEmpty(item->value)) {
                        int count = ParseIntList(item->value, (int*)c->param, lengthof(c->param));
                        if (count < 0) {
                                SetDParamStr(0, filename);
                                ShowErrorMessage(STR_CONFIG_ERROR, STR_CONFIG_ERROR_ARRAY, WL_CRITICAL);
                                count = 0;
                        }
                        c->num_params = count;
                }

                /* Check if item is valid */
                if (!FillGRFDetails(c, is_static) || HasBit(c->flags, GCF_INVALID)) {
                        if (c->status == GCS_NOT_FOUND) {
                                SetDParam(1, STR_CONFIG_ERROR_INVALID_GRF_NOT_FOUND);
                        } else if (HasBit(c->flags, GCF_UNSAFE)) {
                                SetDParam(1, STR_CONFIG_ERROR_INVALID_GRF_UNSAFE);
                        } else if (HasBit(c->flags, GCF_SYSTEM)) {
                                SetDParam(1, STR_CONFIG_ERROR_INVALID_GRF_SYSTEM);
                        } else if (HasBit(c->flags, GCF_INVALID)) {
                                SetDParam(1, STR_CONFIG_ERROR_INVALID_GRF_INCOMPATIBLE);
                        } else {
                                SetDParam(1, STR_CONFIG_ERROR_INVALID_GRF_UNKNOWN);
                        }

                        SetDParamStr(0, StrEmpty(filename) ? item->name : filename);
                        ShowErrorMessage(STR_CONFIG_ERROR, STR_CONFIG_ERROR_INVALID_GRF, WL_CRITICAL);
                        delete c;
                        continue;
                }

                /* Check for duplicate GRFID (will also check for duplicate filenames) */
                bool duplicate = false;
                for (const GRFConfig *gc = first; gc != NULL; gc = gc->next) {
                        if (gc->ident.grfid == c->ident.grfid) {
                                SetDParamStr(0, c->filename);
                                SetDParamStr(1, gc->filename);
                                ShowErrorMessage(STR_CONFIG_ERROR, STR_CONFIG_ERROR_DUPLICATE_GRFID, WL_CRITICAL);
                                duplicate = true;
                                break;
                        }
                }
                if (duplicate) {
                        delete c;
                        continue;
                }

                /* Mark file as static to avoid saving in savegame. */
                if (is_static) SetBit(c->flags, GCF_STATIC);

                /* Add item to list */
                *curr = c;
                curr = &c->next;
        }

        return first;
}

static void AISaveConfig(IniFile *ini, const char *grpname)
{
        IniGroup *group = ini->GetGroup(grpname);

        if (group == NULL) return;
        group->Clear();

        for (CompanyID c = COMPANY_FIRST; c < MAX_COMPANIES; c++) {
                AIConfig *config = AIConfig::GetConfig(c, AIConfig::SSS_FORCE_NEWGAME);
                const char *name;
                char value[1024];
                config->SettingsToString(value, lastof(value));

                if (config->HasScript()) {
                        name = config->GetName();
                } else {
                        name = "none";
                }

                IniItem *item = new IniItem(group, name);
                item->SetValue(value);
        }
}

static void GameSaveConfig(IniFile *ini, const char *grpname)
{
        IniGroup *group = ini->GetGroup(grpname);

        if (group == NULL) return;
        group->Clear();

        GameConfig *config = GameConfig::GetConfig(AIConfig::SSS_FORCE_NEWGAME);
        const char *name;
        char value[1024];
        config->SettingsToString(value, lastof(value));

        if (config->HasScript()) {
                name = config->GetName();
        } else {
                name = "none";
        }

        IniItem *item = new IniItem(group, name);
        item->SetValue(value);
}

/**
 * Save the version of OpenTTD to the ini file.
 * @param ini the ini to write to
 */
static void SaveVersionInConfig(IniFile *ini)
{
        IniGroup *group = ini->GetGroup("version");

        char version[9];
        seprintf(version, lastof(version), "%08X", _openttd_newgrf_version);

        const char * const versions[][2] = {
                { "version_string", _openttd_revision },
                { "version_number", version }
        };

        for (uint i = 0; i < lengthof(versions); i++) {
                group->GetItem(versions[i][0], true)->SetValue(versions[i][1]);
        }
}

/* Save a GRF configuration to the given group name */
static void GRFSaveConfig(IniFile *ini, const char *grpname, const GRFConfig *list)
{
        ini->RemoveGroup(grpname);
        IniGroup *group = ini->GetGroup(grpname);
        const GRFConfig *c;

        for (c = list; c != NULL; c = c->next) {
                /* Hex grfid (4 bytes in nibbles), "|", hex md5sum (16 bytes in nibbles), "|", file system path. */
                char key[4 * 2 + 1 + 16 * 2 + 1 + MAX_PATH];
                char params[512];
                GRFBuildParamList(params, c, lastof(params));

                char *pos = key + seprintf(key, lastof(key), "%08X|", BSWAP32(c->ident.grfid));
                pos = md5sumToString(pos, lastof(key), c->ident.md5sum);
                seprintf(pos, lastof(key), "|%s", c->filename);
                group->GetItem(key, true)->SetValue(params);
        }
}

/* Common handler for saving/loading variables to the configuration file */
static void HandleSettingDescs(IniFile *ini, SettingDescProc *proc, SettingDescProcList *proc_list, bool basic_settings = true, bool other_settings = true)
{
        if (basic_settings) {
                proc(ini, (const SettingDesc*)_misc_settings,    "misc",  NULL);
#if defined(WIN32) && !defined(DEDICATED)
                proc(ini, (const SettingDesc*)_win32_settings,   "win32", NULL);
#endif /* WIN32 */
        }

        if (other_settings) {
                proc(ini, _settings,         "patches",  &_settings_newgame);
                proc(ini, _currency_settings,"currency", &_custom_currency);
                proc(ini, _company_settings, "company",  &_settings_client.company);

#ifdef ENABLE_NETWORK
                proc_list(ini, "server_bind_addresses", &_network_bind_list);
                proc_list(ini, "servers", &_network_host_list);
                proc_list(ini, "bans",    &_network_ban_list);
#endif /* ENABLE_NETWORK */
        }
}

static IniFile *IniLoadConfig()
{
        IniFile *ini = new IniFile(_list_group_names);
        ini->LoadFromDisk(_config_file, NO_DIRECTORY);
        return ini;
}

/**
 * Load the values from the configuration files
 * @param minimal Load the minimal amount of the configuration to "bootstrap" the blitter and such.
 */
void LoadFromConfig(bool minimal)
{
        IniFile *ini = IniLoadConfig();
        if (!minimal) ResetCurrencies(false); // Initialize the array of currencies, without preserving the custom one

        /* Load basic settings only during bootstrap, load other settings not during bootstrap */
        HandleSettingDescs(ini, IniLoadSettings, IniLoadSettingList, minimal, !minimal);

        if (!minimal) {
                _grfconfig_newgame = GRFLoadConfig(ini, "newgrf", false);
                _grfconfig_static  = GRFLoadConfig(ini, "newgrf-static", true);
                AILoadConfig(ini, "ai_players");
                GameLoadConfig(ini, "game_scripts");

                PrepareOldDiffCustom();
                IniLoadSettings(ini, _gameopt_settings, "gameopt", &_settings_newgame);
                HandleOldDiffCustom(false);

                ValidateSettings();

                /* Display sheduled errors */
                extern void ScheduleErrorMessage(ErrorList &datas);
                ScheduleErrorMessage(_settings_error_list);
                if (FindWindowById(WC_ERRMSG, 0) == NULL) ShowFirstError();
        }

        delete ini;
}

/** Save the values to the configuration file */
void SaveToConfig()
{
        IniFile *ini = IniLoadConfig();

        /* Remove some obsolete groups. These have all been loaded into other groups. */
        ini->RemoveGroup("patches");
        ini->RemoveGroup("yapf");
        ini->RemoveGroup("gameopt");

        HandleSettingDescs(ini, IniSaveSettings, IniSaveSettingList);
        GRFSaveConfig(ini, "newgrf", _grfconfig_newgame);
        GRFSaveConfig(ini, "newgrf-static", _grfconfig_static);
        AISaveConfig(ini, "ai_players");
        GameSaveConfig(ini, "game_scripts");
        SaveVersionInConfig(ini);
        ini->SaveToDisk(_config_file);
        delete ini;
}

/**
 * Get the list of known NewGrf presets.
 * @param list[inout] Pointer to list for storing the preset names.
 */
void GetGRFPresetList(GRFPresetList *list)
{
        list->Clear();

        IniFile *ini = IniLoadConfig();
        IniGroup *group;
        for (group = ini->group; group != NULL; group = group->next) {
                if (strncmp(group->name, "preset-", 7) == 0) {
                        *list->Append() = stredup(group->name + 7);
                }
        }

        delete ini;
}

/**
 * Load a NewGRF configuration by preset-name.
 * @param config_name Name of the preset.
 * @return NewGRF configuration.
 * @see GetGRFPresetList
 */
GRFConfig *LoadGRFPresetFromConfig(const char *config_name)
{
        size_t len = strlen(config_name) + 8;
        char *section = (char*)alloca(len);
        seprintf(section, section + len - 1, "preset-%s", config_name);

        IniFile *ini = IniLoadConfig();
        GRFConfig *config = GRFLoadConfig(ini, section, false);
        delete ini;

        return config;
}

/**
 * Save a NewGRF configuration with a preset name.
 * @param config_name Name of the preset.
 * @param config      NewGRF configuration to save.
 * @see GetGRFPresetList
 */
void SaveGRFPresetToConfig(const char *config_name, GRFConfig *config)
{
        size_t len = strlen(config_name) + 8;
        char *section = (char*)alloca(len);
        seprintf(section, section + len - 1, "preset-%s", config_name);

        IniFile *ini = IniLoadConfig();
        GRFSaveConfig(ini, section, config);
        ini->SaveToDisk(_config_file);
        delete ini;
}

/**
 * Delete a NewGRF configuration by preset name.
 * @param config_name Name of the preset.
 */
void DeleteGRFPresetFromConfig(const char *config_name)
{
        size_t len = strlen(config_name) + 8;
        char *section = (char*)alloca(len);
        seprintf(section, section + len - 1, "preset-%s", config_name);

        IniFile *ini = IniLoadConfig();
        ini->RemoveGroup(section);
        ini->SaveToDisk(_config_file);
        delete ini;
}

const SettingDesc *GetSettingDescription(uint index)
{
        if (index >= lengthof(_settings)) return NULL;
        return &_settings[index];
}

/**
 * Network-safe changing of settings (server-only).
 * @param tile unused
 * @param flags operation to perform
 * @param p1 the index of the setting in the SettingDesc array which identifies it
 * @param p2 the new value for the setting
 * The new value is properly clamped to its minimum/maximum when setting
 * @param text unused
 * @return the cost of this operation or an error
 * @see _settings
 */
CommandCost CmdChangeSetting(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
{
        const SettingDesc *sd = GetSettingDescription(p1);

        if (sd == NULL) return CMD_ERROR;
        if (!SlIsObjectCurrentlyValid(sd->save.version_from, sd->save.version_to)) return CMD_ERROR;

        if (!sd->IsEditable(true)) return CMD_ERROR;

        if (flags & DC_EXEC) {
                void *var = GetVariableAddress(&GetGameSettings(), &sd->save);

                int32 oldval = (int32)ReadValue(var, sd->save.conv);
                int32 newval = (int32)p2;

                Write_ValidateSetting(var, sd, newval);
                newval = (int32)ReadValue(var, sd->save.conv);

                if (oldval == newval) return CommandCost();

                if (sd->desc.proc != NULL && !sd->desc.proc(newval)) {
                        WriteValue(var, sd->save.conv, (int64)oldval);
                        return CommandCost();
                }

                if (sd->desc.flags & SGF_NO_NETWORK) {
                        GamelogStartAction(GLAT_SETTING);
                        GamelogSetting(sd->desc.name, oldval, newval);
                        GamelogStopAction();
                }

                SetWindowClassesDirty(WC_GAME_OPTIONS);
        }

        return CommandCost();
}

/**
 * Change one of the per-company settings.
 * @param tile unused
 * @param flags operation to perform
 * @param p1 the index of the setting in the _company_settings array which identifies it
 * @param p2 the new value for the setting
 * The new value is properly clamped to its minimum/maximum when setting
 * @param text unused
 * @return the cost of this operation or an error
 */
CommandCost CmdChangeCompanySetting(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
{
        if (p1 >= lengthof(_company_settings)) return CMD_ERROR;
        const SettingDesc *sd = &_company_settings[p1];

        if (flags & DC_EXEC) {
                void *var = GetVariableAddress(&Company::Get(_current_company)->settings, &sd->save);

                int32 oldval = (int32)ReadValue(var, sd->save.conv);
                int32 newval = (int32)p2;

                Write_ValidateSetting(var, sd, newval);
                newval = (int32)ReadValue(var, sd->save.conv);

                if (oldval == newval) return CommandCost();

                if (sd->desc.proc != NULL && !sd->desc.proc(newval)) {
                        WriteValue(var, sd->save.conv, (int64)oldval);
                        return CommandCost();
                }

                SetWindowClassesDirty(WC_GAME_OPTIONS);
        }

        return CommandCost();
}

/**
 * Top function to save the new value of an element of the Settings struct
 * @param index offset in the SettingDesc array of the Settings struct which
 * identifies the setting member we want to change
 * @param value new value of the setting
 * @param force_newgame force the newgame settings
 */
bool SetSettingValue(uint index, int32 value, bool force_newgame)
{
        const SettingDesc *sd = &_settings[index];
        /* If an item is company-based, we do not send it over the network
         * (if any) to change. Also *hack*hack* we update the _newgame version
         * of settings because changing a company-based setting in a game also
         * changes its defaults. At least that is the convention we have chosen */
        if (sd->save.conv & SLF_NO_NETWORK_SYNC) {
                void *var = GetVariableAddress(&GetGameSettings(), &sd->save);
                Write_ValidateSetting(var, sd, value);

                if (_game_mode != GM_MENU) {
                        void *var2 = GetVariableAddress(&_settings_newgame, &sd->save);
                        Write_ValidateSetting(var2, sd, value);
                }
                if (sd->desc.proc != NULL) sd->desc.proc((int32)ReadValue(var, sd->save.conv));

                SetWindowClassesDirty(WC_GAME_OPTIONS);

                return true;
        }

        if (force_newgame) {
                void *var2 = GetVariableAddress(&_settings_newgame, &sd->save);
                Write_ValidateSetting(var2, sd, value);
                return true;
        }

        /* send non-company-based settings over the network */
        if (!_networking || (_networking && _network_server)) {
                return DoCommandP(0, index, value, CMD_CHANGE_SETTING);
        }
        return false;
}

/**
 * Top function to save the new value of an element of the Settings struct
 * @param index offset in the SettingDesc array of the CompanySettings struct
 * which identifies the setting member we want to change
 * @param value new value of the setting
 */
void SetCompanySetting(uint index, int32 value)
{
        const SettingDesc *sd = &_company_settings[index];
        if (Company::IsValidID(_local_company) && _game_mode != GM_MENU) {
                DoCommandP(0, index, value, CMD_CHANGE_COMPANY_SETTING);
        } else {
                void *var = GetVariableAddress(&_settings_client.company, &sd->save);
                Write_ValidateSetting(var, sd, value);
                if (sd->desc.proc != NULL) sd->desc.proc((int32)ReadValue(var, sd->save.conv));
        }
}

/**
 * Set the company settings for a new company to their default values.
 */
void SetDefaultCompanySettings(CompanyID cid)
{
        Company *c = Company::Get(cid);
        const SettingDesc *sd;
        for (sd = _company_settings; sd->save.cmd != SL_END; sd++) {
                void *var = GetVariableAddress(&c->settings, &sd->save);
                Write_ValidateSetting(var, sd, (int32)(size_t)sd->desc.def);
        }
}

#if defined(ENABLE_NETWORK)
/**
 * Sync all company settings in a multiplayer game.
 */
void SyncCompanySettings()
{
        const SettingDesc *sd;
        uint i = 0;
        for (sd = _company_settings; sd->save.cmd != SL_END; sd++, i++) {
                const void *old_var = GetVariableAddress(&Company::Get(_current_company)->settings, &sd->save);
                const void *new_var = GetVariableAddress(&_settings_client.company, &sd->save);
                uint32 old_value = (uint32)ReadValue(old_var, sd->save.conv);
                uint32 new_value = (uint32)ReadValue(new_var, sd->save.conv);
                if (old_value != new_value) NetworkSendCommand(0, i, new_value, CMD_CHANGE_COMPANY_SETTING, NULL, NULL, _local_company);
        }
}
#endif /* ENABLE_NETWORK */

/**
 * Get the index in the _company_settings array of a setting
 * @param name The name of the setting
 * @return The index in the _company_settings array
 */
uint GetCompanySettingIndex(const char *name)
{
        uint i;
        const SettingDesc *sd = GetSettingFromName(name, &i);
        assert(sd != NULL && (sd->desc.flags & SGF_PER_COMPANY) != 0);
        return i;
}

/**
 * Set a setting value with a string.
 * @param index the settings index.
 * @param value the value to write
 * @param force_newgame force the newgame settings
 * @note Strings WILL NOT be synced over the network
 */
bool SetSettingValue(uint index, const char *value, bool force_newgame)
{
        const SettingDesc *sd = &_settings[index];
        assert(sd->save.conv & SLF_NO_NETWORK_SYNC);

        if (GetVarMemType(sd->save.conv) == SLE_VAR_STRQ) {
                char **var = (char**)GetVariableAddress((_game_mode == GM_MENU || force_newgame) ? &_settings_newgame : &_settings_game, &sd->save);
                free(*var);
                *var = strcmp(value, "(null)") == 0 ? NULL : stredup(value);
        } else {
                char *var = (char*)GetVariableAddress(NULL, &sd->save);
                strecpy(var, value, &var[sd->save.length - 1]);
        }
        if (sd->desc.proc != NULL) sd->desc.proc(0);

        return true;
}

/**
 * Given a name of setting, return a setting description of it.
 * @param name  Name of the setting to return a setting description of
 * @param i     Pointer to an integer that will contain the index of the setting after the call, if it is successful.
 * @return Pointer to the setting description of setting \a name if it can be found,
 *         \c NULL indicates failure to obtain the description
 */
const SettingDesc *GetSettingFromName(const char *name, uint *i)
{
        const SettingDesc *sd;

        /* First check all full names */
        for (*i = 0, sd = _settings; sd->save.cmd != SL_END; sd++, (*i)++) {
                if (!SlIsObjectCurrentlyValid(sd->save.version_from, sd->save.version_to)) continue;
                if (strcmp(sd->desc.name, name) == 0) return sd;
        }

        /* Then check the shortcut variant of the name. */
        for (*i = 0, sd = _settings; sd->save.cmd != SL_END; sd++, (*i)++) {
                if (!SlIsObjectCurrentlyValid(sd->save.version_from, sd->save.version_to)) continue;
                const char *short_name = strchr(sd->desc.name, '.');
                if (short_name != NULL) {
                        short_name++;
                        if (strcmp(short_name, name) == 0) return sd;
                }
        }

        if (strncmp(name, "company.", 8) == 0) name += 8;
        /* And finally the company-based settings */
        for (*i = 0, sd = _company_settings; sd->save.cmd != SL_END; sd++, (*i)++) {
                if (!SlIsObjectCurrentlyValid(sd->save.version_from, sd->save.version_to)) continue;
                if (strcmp(sd->desc.name, name) == 0) return sd;
        }

        return NULL;
}

/* Those 2 functions need to be here, else we have to make some stuff non-static
 * and besides, it is also better to keep stuff like this at the same place */
void IConsoleSetSetting(const char *name, const char *value, bool force_newgame)
{
        uint index;
        const SettingDesc *sd = GetSettingFromName(name, &index);

        if (sd == NULL) {
                IConsolePrintF(CC_WARNING, "'%s' is an unknown setting.", name);
                return;
        }

        bool success;
        if (sd->desc.cmd == SDT_STRING) {
                success = SetSettingValue(index, value, force_newgame);
        } else {
                uint32 val;
                extern bool GetArgumentInteger(uint32 *value, const char *arg);
                success = GetArgumentInteger(&val, value);
                if (!success) {
                        IConsolePrintF(CC_ERROR, "'%s' is not an integer.", value);
                        return;
                }

                success = SetSettingValue(index, val, force_newgame);
        }

        if (!success) {
                if (_network_server) {
                        IConsoleError("This command/variable is not available during network games.");
                } else {
                        IConsoleError("This command/variable is only available to a network server.");
                }
        }
}

void IConsoleSetSetting(const char *name, int value)
{
        uint index;
        const SettingDesc *sd = GetSettingFromName(name, &index);
        assert(sd != NULL);
        SetSettingValue(index, value);
}

/**
 * Output value of a specific setting to the console
 * @param name  Name of the setting to output its value
 * @param force_newgame force the newgame settings
 */
void IConsoleGetSetting(const char *name, bool force_newgame)
{
        char value[20];
        uint index;
        const SettingDesc *sd = GetSettingFromName(name, &index);
        const void *ptr;

        if (sd == NULL) {
                IConsolePrintF(CC_WARNING, "'%s' is an unknown setting.", name);
                return;
        }

        ptr = GetVariableAddress((_game_mode == GM_MENU || force_newgame) ? &_settings_newgame : &_settings_game, &sd->save);

        if (sd->desc.cmd == SDT_STRING) {
                IConsolePrintF(CC_WARNING, "Current value for '%s' is: '%s'", name, (GetVarMemType(sd->save.conv) == SLE_VAR_STRQ) ? *(const char * const *)ptr : (const char *)ptr);
        } else {
                if (sd->desc.cmd == SDT_BOOLX) {
                        seprintf(value, lastof(value), (*(const bool*)ptr != 0) ? "on" : "off");
                } else {
                        seprintf(value, lastof(value), sd->desc.min < 0 ? "%d" : "%u", (int32)ReadValue(ptr, sd->save.conv));
                }

                IConsolePrintF(CC_WARNING, "Current value for '%s' is: '%s' (min: %s%d, max: %u)",
                        name, value, (sd->desc.flags & SGF_0ISDISABLED) ? "(0) " : "", sd->desc.min, sd->desc.max);
        }
}

/**
 * List all settings and their value to the console
 *
 * @param prefilter  If not \c NULL, only list settings with names that begin with \a prefilter prefix
 */
void IConsoleListSettings(const char *prefilter)
{
        IConsolePrintF(CC_WARNING, "All settings with their current value:");

        for (const SettingDesc *sd = _settings; sd->save.cmd != SL_END; sd++) {
                if (!SlIsObjectCurrentlyValid(sd->save.version_from, sd->save.version_to)) continue;
                if (prefilter != NULL && strstr(sd->desc.name, prefilter) == NULL) continue;
                char value[80];
                const void *ptr = GetVariableAddress(&GetGameSettings(), &sd->save);

                if (sd->desc.cmd == SDT_BOOLX) {
                        seprintf(value, lastof(value), (*(const bool *)ptr != 0) ? "on" : "off");
                } else if (sd->desc.cmd == SDT_STRING) {
                        seprintf(value, lastof(value), "%s", (GetVarMemType(sd->save.conv) == SLE_VAR_STRQ) ? *(const char * const *)ptr : (const char *)ptr);
                } else {
                        seprintf(value, lastof(value), sd->desc.min < 0 ? "%d" : "%u", (int32)ReadValue(ptr, sd->save.conv));
                }
                IConsolePrintF(CC_DEFAULT, "%s = %s", sd->desc.name, value);
        }

        IConsolePrintF(CC_WARNING, "Use 'setting' command to change a value");
}

/**
 * Save and load handler for settings
 * @param osd SettingDesc struct containing all information
 * @param object can be either NULL in which case we load global variables or
 * a pointer to a struct which is getting saved
 */
static void LoadSettings(const SettingDesc *osd, void *object)
{
        for (; osd->save.cmd != SL_END; osd++) {
                const SaveLoad *sld = &osd->save;
                void *ptr = GetVariableAddress(object, sld);

                if (!SlObjectMember(ptr, sld)) continue;
                if (IsNumericType(sld->conv)) Write_ValidateSetting(ptr, osd, ReadValue(ptr, sld->conv));
        }
}

/**
 * Save and load handler for settings
 * @param sd SettingDesc struct containing all information
 * @param object can be either NULL in which case we load global variables or
 * a pointer to a struct which is getting saved
 */
static void SaveSettings(const SettingDesc *sd, void *object)
{
        /* We need to write the CH_RIFF header, but unfortunately can't call
         * SlCalcLength() because we have a different format. So do this manually */
        const SettingDesc *i;
        size_t length = 0;
        for (i = sd; i->save.cmd != SL_END; i++) {
                length += SlCalcObjMemberLength(object, &i->save);
        }
        SlSetLength(length);

        for (i = sd; i->save.cmd != SL_END; i++) {
                void *ptr = GetVariableAddress(object, &i->save);
                SlObjectMember(ptr, &i->save);
        }
}

static void Load_OPTS()
{
        /* Copy over default setting since some might not get loaded in
         * a networking environment. This ensures for example that the local
         * autosave-frequency stays when joining a network-server */
        PrepareOldDiffCustom();
        LoadSettings(_gameopt_settings, &_settings_game);
        HandleOldDiffCustom(true);
}

static void Load_PATS()
{
        /* Copy over default setting since some might not get loaded in
         * a networking environment. This ensures for example that the local
         * currency setting stays when joining a network-server */
        LoadSettings(_settings, &_settings_game);
}

static void Check_PATS()
{
        LoadSettings(_settings, &_load_check_data.settings);
}

static void Save_PATS()
{
        SaveSettings(_settings, &_settings_game);
}

void CheckConfig()
{
        /*
         * Increase old default values for pf_maxdepth and pf_maxlength
         * to support big networks.
         */
        if (_settings_newgame.pf.opf.pf_maxdepth == 16 && _settings_newgame.pf.opf.pf_maxlength == 512) {
                _settings_newgame.pf.opf.pf_maxdepth = 48;
                _settings_newgame.pf.opf.pf_maxlength = 4096;
        }
}

extern const ChunkHandler _setting_chunk_handlers[] = {
        { 'OPTS', NULL,      Load_OPTS, NULL, NULL,       CH_RIFF},
        { 'PATS', Save_PATS, Load_PATS, NULL, Check_PATS, CH_RIFF | CH_LAST},
};

static bool IsSignedVarMemType(VarType vt)
{
        switch (GetVarMemType(vt)) {
                case SLE_VAR_I8:
                case SLE_VAR_I16:
                case SLE_VAR_I32:
                case SLE_VAR_I64:
                        return true;
        }
        return false;
}