Warning, file /frameworks/kdelibs4support/src/kdecore/ksystemtimezone.cpp was not indexed or was modified since last indexation (in which case cross-reference links may be missing, inaccurate or erroneous).

 /*
    This file is part of the KDE libraries
    Copyright (c) 2005-2010 David Jarvie <djarvie@kde.org>
    Copyright (c) 2005 S.R.Haque <srhaque@iee.org>.
 
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.
 
    This library 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
    Library General Public License for more details.
 
    You should have received a copy of the GNU Library General Public License
    along with this library; see the file COPYING.LIB.  If not, write to
    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
    Boston, MA 02110-1301, USA.
 */
 
 // This file requires HAVE_STRUCT_TM_TM_ZONE to be defined if struct tm member tm_zone is available.
 // This file requires HAVE_TM_GMTOFF to be defined if struct tm member tm_gmtoff is available.
 
 #include "moc_ksystemtimezone.cpp"
 
 #include <config-date.h>
 
 #if HAVE_SYS_TIME_H
 #include <sys/time.h>
 #endif
 #if HAVE_TIME_H
 #include <time.h>
 #endif
 #include <climits>
 #include <cstdlib>
 
 #include <QDebug>
 #include <QCoreApplication>
 #include <QFile>
 #include <QFileInfo>
 #include <QDir>
 #include <QRegExp>
 #include <QStringList>
 #include <QTextStream>
 #include <QDBusConnection>
 #include <QDBusInterface>
 #include <QDBusConnectionInterface>
 #include <QDBusReply>
 
 #include <kconfig.h>
 #include <klocalizedstring.h>
 #include <kstringhandler.h>
 #include <kconfiggroup.h>
 #include "ktzfiletimezone.h"
 #ifdef Q_OS_WIN
 #include "ktimezone_win.h"
 #endif
 
 #define KTIMEZONED_DBUS_IFACE "org.kde.KTimeZoned"
 
 /* Return the offset to UTC in the current time zone at the specified UTC time.
  * The thread-safe function localtime_r() is used in preference if available.
  */
 int gmtoff(time_t t)
 {
 #ifdef _POSIX_THREAD_SAFE_FUNCTIONS
     tm tmtime;
     if (!localtime_r(&t, &tmtime)) {
         return 0;
     }
 #if HAVE_TM_GMTOFF
     return tmtime.tm_gmtoff;
 #else
     int lwday = tmtime.tm_wday;
     int lt = 3600 * tmtime.tm_hour + 60 * tmtime.tm_min + tmtime.tm_sec;
     if (!gmtime_r(&t, &tmtime)) {
         return 0;
     }
     int uwday = tmtime.tm_wday;
     int ut = 3600 * tmtime.tm_hour + 60 * tmtime.tm_min + tmtime.tm_sec;
 #endif
 #else
     tm *tmtime = localtime(&t);
     if (!tmtime) {
         return 0;
     }
 #if HAVE_TM_GMTOFF
     return tmtime->tm_gmtoff;
 #else
     int lwday = tmtime->tm_wday;
     int lt = 3600 * tmtime->tm_hour + 60 * tmtime->tm_min + tmtime->tm_sec;
     tmtime = gmtime(&t);
     int uwday = tmtime->tm_wday;
     int ut = 3600 * tmtime->tm_hour + 60 * tmtime->tm_min + tmtime->tm_sec;
 #endif
 #endif
 #if ! HAVE_TM_GMTOFF
     if (lwday != uwday) {
         // Adjust for different day
         if (lwday == uwday + 1  || (lwday == 0 && uwday == 6)) {
             lt += 24 * 3600;
         } else {
             lt -= 24 * 3600;
         }
     }
     return lt - ut;
 #endif
 }
 
 /******************************************************************************/
 
 class KSystemTimeZonesPrivate : public KTimeZones
 {
 public:
     static KSystemTimeZonesPrivate *instance();
     static KTzfileTimeZoneSource *tzfileSource();
     static void setLocalZone();
     static void cleanup();
     static void readConfig(bool init);
 #ifdef Q_OS_WIN
     static void updateTimezoneInformation()
     {
         instance()->updateTimezoneInformation(true);
     }
 #else
     static void updateZonetab()
     {
         instance()->readZoneTab(true);
     }
 #endif
 
     static KTimeZone m_localZone;
     static QString m_localZoneName;
     static QString m_zoneinfoDir;
     static QString m_zonetab;
     static KSystemTimeZoneSource *m_source;
     static bool m_ktimezonedError;
 
 private:
     KSystemTimeZonesPrivate() {}
 #ifdef Q_OS_WIN
     void updateTimezoneInformation(bool update);
 #else
     void readZoneTab(bool update);
     static float convertCoordinate(const QString &coordinate);
 #endif
 
     static KSystemTimeZones *m_parent;
     static KSystemTimeZonesPrivate *m_instance;
     static KTzfileTimeZoneSource *m_tzfileSource;
 };
 
 KTimeZone                KSystemTimeZonesPrivate::m_localZone;
 QString                  KSystemTimeZonesPrivate::m_localZoneName;
 QString                  KSystemTimeZonesPrivate::m_zoneinfoDir;
 QString                  KSystemTimeZonesPrivate::m_zonetab;
 KSystemTimeZoneSource   *KSystemTimeZonesPrivate::m_source = nullptr;
 bool                     KSystemTimeZonesPrivate::m_ktimezonedError = true;
 KTzfileTimeZoneSource   *KSystemTimeZonesPrivate::m_tzfileSource = nullptr;
 KSystemTimeZones        *KSystemTimeZonesPrivate::m_parent = nullptr;
 KSystemTimeZonesPrivate *KSystemTimeZonesPrivate::m_instance = nullptr;
 
 KTzfileTimeZoneSource *KSystemTimeZonesPrivate::tzfileSource()
 {
     if (!m_tzfileSource) {
         instance();
         m_tzfileSource = new KTzfileTimeZoneSource(m_zoneinfoDir);
     }
     return m_tzfileSource;
 }
 
 // for the benefit of KTimeZoneTest
 KDELIBS4SUPPORT_EXPORT void k_system_time_zone_private_reset_config()
 {
     // Remove any old zones from the collection
     const KTimeZones::ZoneMap oldZones = KSystemTimeZonesPrivate::instance()->zones();
     for (KTimeZones::ZoneMap::ConstIterator it = oldZones.constBegin();  it != oldZones.constEnd();  ++it) {
         KSystemTimeZonesPrivate::instance()->remove(it.value());
     }
 
     // Read new config file
     KSystemTimeZonesPrivate::readConfig(false);
 }
 
 #ifndef NDEBUG
 Q_GLOBAL_STATIC(KTimeZone, simulatedLocalZone)
 #endif
 
 KSystemTimeZones::KSystemTimeZones()
     : d(nullptr)
 {
     QDBusConnection dbus = QDBusConnection::sessionBus();
     const QString dbusIface = QString::fromLatin1(KTIMEZONED_DBUS_IFACE);
     dbus.connect(QString(), QString(), dbusIface, QLatin1String("timeZoneChanged"), this, SLOT(configChanged()));
     dbus.connect(QString(), QString(), dbusIface, QLatin1String("timeZoneDatabaseUpdated"), this, SLOT(zonetabChanged(QString)));
     // No need to connect to definitionChanged() - see comments in zoneDefinitionChanged()
     //dbus.connect(QString(), QString(), dbusIface, QLatin1String("definitionChanged"), this, SLOT(zoneDefinitionChanged(QString)));
 }
 
 KSystemTimeZones::~KSystemTimeZones()
 {
 }
 
 KTimeZone KSystemTimeZones::local()
 {
 #ifndef NDEBUG
     if (simulatedLocalZone()->isValid()) {
         return *simulatedLocalZone();
     }
 #endif
     KSystemTimeZonesPrivate::instance();
     return KSystemTimeZonesPrivate::m_localZone;
 }
 
 KTimeZone KSystemTimeZones::realLocalZone()
 {
     KSystemTimeZonesPrivate::instance();
     return KSystemTimeZonesPrivate::m_localZone;
 }
 
 void KSystemTimeZones::setLocalZone(const KTimeZone &tz)
 {
     Q_UNUSED(tz);
 #ifndef NDEBUG
     *simulatedLocalZone() = tz;
 #endif
 }
 
 bool KSystemTimeZones::isSimulated()
 {
 #ifndef NDEBUG
     return simulatedLocalZone()->isValid();
 #else
     return false;
 #endif
 }
 
 QString KSystemTimeZones::zoneinfoDir()
 {
     KSystemTimeZonesPrivate::instance();
     return KSystemTimeZonesPrivate::m_zoneinfoDir;
 }
 
 bool KSystemTimeZones::isTimeZoneDaemonAvailable()
 {
     KSystemTimeZonesPrivate::instance();
     return !KSystemTimeZonesPrivate::m_ktimezonedError;
 }
 
 KTimeZones *KSystemTimeZones::timeZones()
 {
     return KSystemTimeZonesPrivate::instance();
 }
 
 KTimeZone KSystemTimeZones::readZone(const QString &name)
 {
     return KTzfileTimeZone(KSystemTimeZonesPrivate::tzfileSource(), name);
 }
 
 const KTimeZones::ZoneMap KSystemTimeZones::zones()
 {
     return KSystemTimeZonesPrivate::instance()->zones();
 }
 
 KTimeZone KSystemTimeZones::zone(const QString &name)
 {
     return KSystemTimeZonesPrivate::instance()->zone(name);
 }
 
 void KSystemTimeZones::configChanged()
 {
     //qDebug() << "KSystemTimeZones::configChanged()";
     KSystemTimeZonesPrivate::m_ktimezonedError = false;
     KSystemTimeZonesPrivate::readConfig(false);
 }
 
 void KSystemTimeZones::zonetabChanged(const QString &zonetab)
 {
     Q_UNUSED(zonetab)
 #ifndef Q_OS_WIN
     //qDebug() << "KSystemTimeZones::zonetabChanged()";
     KSystemTimeZonesPrivate::m_ktimezonedError = false;
     // Re-read zone.tab and update our collection, removing any deleted
     // zones and adding any new zones.
     KSystemTimeZonesPrivate::updateZonetab();
 #endif
 }
 
 void KSystemTimeZones::zoneDefinitionChanged(const QString &zone)
 {
     // No need to do anything when the definition (as opposed to the
     // identity) of the local zone changes, since the updated details
     // will always be accessed by the system library calls to fetch
     // local zone information.
     Q_UNUSED(zone)
     KSystemTimeZonesPrivate::m_ktimezonedError = false;
 }
 
 // Perform initialization, create the unique KSystemTimeZones instance,
 // whose only function is to receive D-Bus signals from KTimeZoned,
 // and create the unique KSystemTimeZonesPrivate instance.
 KSystemTimeZonesPrivate *KSystemTimeZonesPrivate::instance()
 {
     if (!m_instance) {
         m_instance = new KSystemTimeZonesPrivate;
 
         // A KSystemTimeZones instance is required only to catch D-Bus signals.
         m_parent = new KSystemTimeZones;
         // Ensure that the KDED time zones module has initialized. The call loads the module on demand.
         QDBusConnectionInterface *bus = QDBusConnection::sessionBus().interface();
         if (!bus->isServiceRegistered(QLatin1String("org.kde.kded5"))) {
             // kded isn't even running: start it
             QDBusReply<void> reply = bus->startService(QLatin1String("org.kde.kded5"));
             if (!reply.isValid()) {
                 qWarning() << "Couldn't start kded5 from org.kde.kded5.service:" << reply.error();
             }
         }
         const QString dbusIface = QString::fromLatin1(KTIMEZONED_DBUS_IFACE);
         QDBusInterface *ktimezoned = new QDBusInterface(QLatin1String("org.kde.kded5"), QLatin1String("/modules/ktimezoned"), dbusIface);
         QDBusReply<void> reply = ktimezoned->call(QLatin1String("initialize"), false);
         m_ktimezonedError = !reply.isValid();
         if (m_ktimezonedError) {
             qCritical() << "KSystemTimeZones: ktimezoned initialize() D-Bus call failed: " << reply.error().message() << endl;
         }
 //qDebug()<<"instance(): ... initialised";
         delete ktimezoned;
 
         // Read the time zone config written by ktimezoned
         readConfig(true);
 
         // Go read the database.
 #ifdef Q_OS_WIN
         // On Windows, HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones
         // is the place to look. The TZI binary value is the TIME_ZONE_INFORMATION structure.
         m_instance->updateTimezoneInformation(false);
 #else
         // For Unix, read zone.tab.
         if (!m_zonetab.isEmpty()) {
             m_instance->readZoneTab(false);
         }
 #endif
         setLocalZone();
 
         qAddPostRoutine(KSystemTimeZonesPrivate::cleanup);
     }
     return m_instance;
 }
 
 void KSystemTimeZonesPrivate::readConfig(bool init)
 {
     KConfig config(QLatin1String("ktimezonedrc"));
     if (!init) {
         config.reparseConfiguration();
     }
     KConfigGroup group(&config, "TimeZones");
     if (!group.exists()) {
         qCritical() << "No time zone information obtained from ktimezoned";
         m_ktimezonedError = true;
     }
     m_zoneinfoDir   = group.readEntry("ZoneinfoDir");
     m_zonetab       = group.readEntry("Zonetab");
     m_localZoneName = group.readEntry("LocalZone");
     if (m_zoneinfoDir.length() > 1 && m_zoneinfoDir.endsWith(QLatin1Char('/'))) {
         m_zoneinfoDir.truncate(m_zoneinfoDir.length() - 1);    // strip trailing '/'
     }
     if (!init) {
 #ifdef Q_OS_WIN
         updateTimezoneInformation();
 #else
         updateZonetab();
 #endif
         setLocalZone();
     }
     //qDebug() << "readConfig(): local zone=" << m_localZoneName;
 }
 
 void KSystemTimeZonesPrivate::setLocalZone()
 {
     // Check whether the local zone name is set at all
     if (m_localZoneName.isEmpty()) {
         m_localZone = KTimeZone::utc();
         return;
     }
 
     // Check if the zone name is a known zone
     if (m_instance) {
         m_localZone = m_instance->zone(m_localZoneName);
         if (m_localZone.isValid()) {
             return;
         }
     }
 
     QString filename;
     if (m_localZoneName.startsWith(QLatin1Char('/'))) {
         // The time zone is specified by a file outside the zoneinfo directory
         filename = m_localZoneName;
     } else {
         // The zone name is specified by a relative file name in zoneinfo directory.
         filename = m_zoneinfoDir + QLatin1Char('/') + m_localZoneName;
     }
 
     // Verify that the time zone file actually exists
     if (!QFile::exists(filename)) {
         m_localZone = KTimeZone::utc();
         return;
     }
 
     // Parse the specified time zone data file
     QString zonename = filename;
     if (zonename.startsWith(m_zoneinfoDir + QLatin1Char('/'))) {
         zonename = zonename.mid(m_zoneinfoDir.length() + 1);
     }
     m_localZone = KTzfileTimeZone(KSystemTimeZonesPrivate::tzfileSource(), zonename);
 
     // Add the new time zone to the list of known time zones
     if (m_instance) {
         const KTimeZone oldzone = m_instance->zone(zonename);
         if (!oldzone.isValid() || oldzone.type() != "KTzfileTimeZone") {
             m_instance->remove(oldzone);
             m_instance->add(m_localZone);
         }
     }
 }
 
 void KSystemTimeZonesPrivate::cleanup()
 {
     delete m_parent;
     delete m_instance;
     delete m_source;
     delete m_tzfileSource;
 }
 
 #ifdef Q_OS_WIN
 
 void KSystemTimeZonesPrivate::updateTimezoneInformation(bool update)
 {
     if (!m_source) {
         m_source = new KSystemTimeZoneSourceWindows;
     }
     QStringList newZones;
     Q_FOREACH (const QString &tz, KSystemTimeZoneWindows::listTimeZones()) {
         // const std::wstring wstr = tz.toStdWString();
         // const KTimeZone info = make_time_zone( wstr.c_str() );
         KSystemTimeZoneWindows stz(m_source, tz);
         if (update) {
             // Update the existing collection with the new zone definition
             newZones += stz.name();
             KTimeZone oldTz = zone(stz.name());
             if (oldTz.isValid()) {
                 oldTz.updateBase(stz);    // the zone previously existed, so update its definition
             } else {
                 add(stz);    // the zone didn't previously exist, so add it
             }
         } else {
             add(stz);
         }
     }
     if (update) {
         // Remove any zones from the collection which no longer exist
         const ZoneMap oldZones = zones();
         for (ZoneMap::const_iterator it = oldZones.begin();  it != oldZones.end();  ++it) {
             if (newZones.indexOf(it.key()) < 0) {
                 remove(it.value());
             }
         }
     }
 }
 
 #else
 /*
  * Find the location of the zoneinfo files and store in mZoneinfoDir.
  * Parse zone.tab and for each time zone, create a KSystemTimeZone instance.
  */
 void KSystemTimeZonesPrivate::readZoneTab(bool update)
 {
     //qDebug() << "readZoneTab(" << m_zonetab<< ")";
     QStringList newZones;
     QFile f;
     f.setFileName(m_zonetab);
     if (!f.open(QIODevice::ReadOnly)) {
         return;
     }
     QTextStream str(&f);
     const QRegExp lineSeparator(QLatin1String("[ \t]"));
     const QRegExp ordinateSeparator(QLatin1String("[+-]"));
     if (!m_source) {
         m_source = new KSystemTimeZoneSource;
     }
     while (!str.atEnd()) {
         const QString line = str.readLine();
         if (line.isEmpty() || line[0] == QLatin1Char('#')) {
             continue;
         }
         QStringList tokens = KStringHandler::perlSplit(lineSeparator, line, 4);
         const int n = tokens.count();
         if (n < 3) {
             qCritical() << "readZoneTab(): invalid record: " << line << endl;
             continue;
         }
 
         // Got three tokens. Now check for two ordinates plus first one is "".
         const int i = tokens[1].indexOf(ordinateSeparator, 1);
         if (i < 0) {
             qCritical() << "readZoneTab() " << tokens[2] << ": invalid coordinates: " << tokens[1] << endl;
             continue;
         }
 
         const float latitude = convertCoordinate(tokens[1].left(i));
         const float longitude = convertCoordinate(tokens[1].mid(i));
 
         // Add entry to list.
         if (tokens[0] == QLatin1String("??")) {
             tokens[0] = QString::fromLatin1("");
         }
         // Solaris sets the empty Comments field to '-', making it not empty.
         // Clean it up.
         if (n > 3  && tokens[3] == QLatin1String("-")) {
             tokens[3] = QString::fromLatin1("");
         }
         // Note: KTzfileTimeZone is used in preference to KSystemTimeZone because of
         //       the large overhead incurred by tzset() - see KSystemTimeZones class
         //       description for details.
         const KTzfileTimeZone tz(tzfileSource(), tokens[2], tokens[0], latitude, longitude, (n > 3 ? tokens[3] : QString()));
         if (update) {
             // Update the existing collection with the new zone definition
             newZones += tz.name();
             KTimeZone oldTz = zone(tz.name());
             if (oldTz.isValid()) {
                 oldTz.updateBase(tz);    // the zone previously existed, so update its definition
             } else {
                 add(tz);    // the zone didn't previously exist, so add it
             }
         } else {
             add(tz);
         }
     }
     f.close();
 
     if (update) {
         // Remove any zones from the collection which no longer exist
         const ZoneMap oldZones = zones();
         for (ZoneMap::ConstIterator it = oldZones.constBegin();  it != oldZones.constEnd();  ++it) {
             if (newZones.indexOf(it.key()) < 0) {
                 remove(it.value());
             }
         }
     }
 }
 
 /**
  * Convert sHHMM or sHHMMSS to a floating point number of degrees.
  */
 float KSystemTimeZonesPrivate::convertCoordinate(const QString &coordinate)
 {
     int value = coordinate.toInt();
     int degrees = 0;
     int minutes = 0;
     int seconds = 0;
 
     if (coordinate.length() > 6) {
         degrees = value / 10000;
         value -= degrees * 10000;
         minutes = value / 100;
         value -= minutes * 100;
         seconds = value;
     } else {
         degrees = value / 100;
         value -= degrees * 100;
         minutes = value;
     }
     value = degrees * 3600 + minutes * 60 + seconds;
     return value / 3600.0;
 }
 #endif
 
 /******************************************************************************/
 
 KSystemTimeZoneBackend::KSystemTimeZoneBackend(KSystemTimeZoneSource *source, const QString &name,
         const QString &countryCode, float latitude, float longitude, const QString &comment)
     : KTimeZoneBackend(source, name, countryCode, latitude, longitude, comment)
 {}
 
 KSystemTimeZoneBackend::~KSystemTimeZoneBackend()
 {}
 
 KTimeZoneBackend *KSystemTimeZoneBackend::clone() const
 {
     return new KSystemTimeZoneBackend(*this);
 }
 
 QByteArray KSystemTimeZoneBackend::type() const
 {
     return "KSystemTimeZone";
 }
 
 int KSystemTimeZoneBackend::offsetAtZoneTime(const KTimeZone *caller, const QDateTime &zoneDateTime, int *secondOffset) const
 {
     if (!caller->isValid()  ||  !zoneDateTime.isValid()  ||  zoneDateTime.timeSpec() != Qt::LocalTime) {
         return 0;
     }
     // Make this time zone the current local time zone
     const QByteArray originalZone = qgetenv("TZ");   // save the original local time zone
     QByteArray tz = caller->name().toUtf8();
     tz.prepend(":");
     const bool change = (tz != originalZone);
     if (change) {
         qputenv("TZ", tz);
         ::tzset();
     }
 
     // Convert zone time to UTC, and then get the offset to UTC
     tm tmtime;
     tmtime.tm_sec    = zoneDateTime.time().second();
     tmtime.tm_min    = zoneDateTime.time().minute();
     tmtime.tm_hour   = zoneDateTime.time().hour();
     tmtime.tm_mday   = zoneDateTime.date().day();
     tmtime.tm_mon    = zoneDateTime.date().month() - 1;
     tmtime.tm_year   = zoneDateTime.date().year() - 1900;
     tmtime.tm_isdst  = -1;
     const time_t t = mktime(&tmtime);
     int offset1 = (t == (time_t) - 1) ? KTimeZone::InvalidOffset : gmtoff(t);
     if (secondOffset) {
         int offset2 = offset1;
         if (t != (time_t) - 1) {
             // Check if there is a backward DST change near to this time, by
             // checking if the UTC offset is different 1 hour later or earlier.
             // ASSUMPTION: DST SHIFTS ARE NEVER GREATER THAN 1 HOUR.
             const int maxShift = 3600;
             offset2 = gmtoff(t + maxShift);
             if (offset2 < offset1) {
                 // There is a backward DST shift during the following hour
                 if (offset1 - offset2 < maxShift) {
                     offset2 = gmtoff(t + (offset1 - offset2));
                 }
             } else if ((offset2 = gmtoff(t - maxShift)) > offset1) {
                 // There is a backward DST shift during the previous hour
                 if (offset2 - offset1 < maxShift) {
                     offset2 = gmtoff(t - (offset2 - offset1));
                 }
                 // Put UTC offsets into the correct order
                 const int o = offset1;
                 offset1 = offset2;
                 offset2 = o;
             } else {
                 offset2 = offset1;
             }
         }
         *secondOffset = offset2;
     }
 
     if (change) {
         // Restore the original local time zone
         if (originalZone.isEmpty()) {
             ::unsetenv("TZ");
         } else {
             qputenv("TZ", originalZone);
         }
         ::tzset();
     }
     return offset1;
 }
 
 int KSystemTimeZoneBackend::offsetAtUtc(const KTimeZone *caller, const QDateTime &utcDateTime) const
 {
     return offset(caller, KTimeZone::toTime_t(utcDateTime));
 }
 
 int KSystemTimeZoneBackend::offset(const KTimeZone *caller, time_t t) const
 {
     if (!caller->isValid()  ||  t == KTimeZone::InvalidTime_t) {
         return 0;
     }
 
     // Make this time zone the current local time zone
     const QByteArray originalZone = qgetenv("TZ");   // save the original local time zone
     QByteArray tz = caller->name().toUtf8();
     tz.prepend(":");
     const bool change = (tz != originalZone);
     if (change) {
         qputenv("TZ", tz);
         ::tzset();
     }
 
     const int secs = gmtoff(t);
 
     if (change) {
         // Restore the original local time zone
         if (originalZone.isEmpty()) {
             ::unsetenv("TZ");
         } else {
             qputenv("TZ", originalZone);
         }
         ::tzset();
     }
     return secs;
 }
 
 bool KSystemTimeZoneBackend::isDstAtUtc(const KTimeZone *caller, const QDateTime &utcDateTime) const
 {
     return isDst(caller, KTimeZone::toTime_t(utcDateTime));
 }
 
 bool KSystemTimeZoneBackend::isDst(const KTimeZone *caller, time_t t) const
 {
     Q_UNUSED(caller)
     if (t != (time_t) - 1) {
 #ifdef _POSIX_THREAD_SAFE_FUNCTIONS
         tm tmtime;
         if (localtime_r(&t, &tmtime)) {
             return tmtime.tm_isdst > 0;
         }
 #else
         const tm *tmtime = localtime(&t);
         if (tmtime) {
             return tmtime->tm_isdst > 0;
         }
 #endif
     }
     return false;
 }
 
 /******************************************************************************/
 
 KSystemTimeZone::KSystemTimeZone(KSystemTimeZoneSource *source, const QString &name,
                                  const QString &countryCode, float latitude, float longitude, const QString &comment)
     : KTimeZone(new KSystemTimeZoneBackend(source, name, countryCode, latitude, longitude, comment))
 {
 }
 
 KSystemTimeZone::~KSystemTimeZone()
 {
 }
 
 /******************************************************************************/
 
 class KSystemTimeZoneDataPrivate
 {
 public:
     QByteArray TZ;
     QList<QByteArray> abbreviations;
 };
 
 // N.B. KSystemTimeZoneSourcePrivate is also used by KSystemTimeZoneData
 class KSystemTimeZoneSourcePrivate
 {
 public:
     static void setTZ(const QByteArray &zoneName);
     static void restoreTZ();
     static QByteArray savedTZ;       // temporary value of TZ environment variable saved by setTZ()
     static QByteArray originalTZ;    // saved value of TZ environment variable during multiple parse() calls
     static bool       TZIsSaved;     // TZ has been saved in savedTZ
     static bool       multiParse;    // true if performing multiple parse() calls
 };
 
 QByteArray KSystemTimeZoneSourcePrivate::savedTZ;
 QByteArray KSystemTimeZoneSourcePrivate::originalTZ;
 bool       KSystemTimeZoneSourcePrivate::TZIsSaved = false;
 bool       KSystemTimeZoneSourcePrivate::multiParse = false;
 
 KSystemTimeZoneSource::KSystemTimeZoneSource()
     : d(nullptr)
 //  : d(new KSystemTimeZoneSourcePrivate)
 {
 }
 
 KSystemTimeZoneSource::~KSystemTimeZoneSource()
 {
 //    delete d;
 }
 
 KTimeZoneData *KSystemTimeZoneSource::parse(const KTimeZone &zone) const
 {
     const QByteArray tz = zone.name().toUtf8();
     KSystemTimeZoneSourcePrivate::setTZ(tz);   // make this time zone the current local time zone
 
     tzset();    // initialize the tzname array
     KSystemTimeZoneData *data = new KSystemTimeZoneData;
     data->d->TZ = tz;
     data->d->abbreviations.append(tzname[0]);
     data->d->abbreviations.append(tzname[1]);
 
     // There is no easy means to access the sequence of daylight savings time
     // changes, or leap seconds adjustments, so leave that data empty.
 
     KSystemTimeZoneSourcePrivate::restoreTZ();   // restore the original local time zone if necessary
     return data;
 }
 
 void KSystemTimeZoneSource::startParseBlock()
 {
     KSystemTimeZoneSourcePrivate::originalTZ = qgetenv("TZ");   // save the original local time zone
     KSystemTimeZoneSourcePrivate::multiParse = true;
 }
 
 void KSystemTimeZoneSource::endParseBlock()
 {
     if (KSystemTimeZoneSourcePrivate::multiParse) {
         // Restore the original local time zone
         if (KSystemTimeZoneSourcePrivate::originalTZ.isEmpty()) {
             ::unsetenv("TZ");
         } else {
             qputenv("TZ", KSystemTimeZoneSourcePrivate::originalTZ);
         }
         ::tzset();
         KSystemTimeZoneSourcePrivate::multiParse = false;
     }
 }
 
 // Set the TZ environment variable to the specified time zone,
 // saving its current setting first if necessary.
 void KSystemTimeZoneSourcePrivate::setTZ(const QByteArray &zoneName)
 {
     QByteArray tz = zoneName;
     tz.prepend(":");
     bool setTZ = multiParse;
     if (!setTZ) {
         savedTZ = qgetenv("TZ");   // save the original local time zone
         TZIsSaved = true;
         setTZ = (tz != savedTZ);
     }
     if (setTZ) {
         qputenv("TZ", tz);
         ::tzset();
     }
 }
 
 // Restore the TZ environment variable if it was saved by setTz()
 void KSystemTimeZoneSourcePrivate::restoreTZ()
 {
     if (TZIsSaved) {
         if (savedTZ.isEmpty()) {
             ::unsetenv("TZ");
         } else {
             qputenv("TZ", savedTZ);
         }
         ::tzset();
         TZIsSaved = false;
     }
 }
 
 /******************************************************************************/
 
 KSystemTimeZoneData::KSystemTimeZoneData()
     : d(new KSystemTimeZoneDataPrivate)
 { }
 
 KSystemTimeZoneData::KSystemTimeZoneData(const KSystemTimeZoneData &rhs)
     : KTimeZoneData(),
       d(new KSystemTimeZoneDataPrivate)
 {
     operator=(rhs);
 }
 
 KSystemTimeZoneData::~KSystemTimeZoneData()
 {
     delete d;
 }
 
 KSystemTimeZoneData &KSystemTimeZoneData::operator=(const KSystemTimeZoneData &rhs)
 {
     d->TZ = rhs.d->TZ;
     d->abbreviations = rhs.d->abbreviations;
     return *this;
 }
 
 KTimeZoneData *KSystemTimeZoneData::clone() const
 {
     return new KSystemTimeZoneData(*this);
 }
 
 QList<QByteArray> KSystemTimeZoneData::abbreviations() const
 {
     return d->abbreviations;
 }
 
 QByteArray KSystemTimeZoneData::abbreviation(const QDateTime &utcDateTime) const
 {
     QByteArray abbr;
     if (utcDateTime.timeSpec() != Qt::UTC) {
         return abbr;
     }
     time_t t = utcDateTime.toTime_t();
     if (t != KTimeZone::InvalidTime_t) {
         KSystemTimeZoneSourcePrivate::setTZ(d->TZ);   // make this time zone the current local time zone
 
         /* Use tm.tm_zone if available because it returns the abbreviation
          * in use at the time specified. Otherwise, use tzname[] which
          * returns the appropriate current abbreviation instead.
          */
 #ifdef _POSIX_THREAD_SAFE_FUNCTIONS
         tm tmtime;
         if (localtime_r(&t, &tmtime))
 #if HAVE_STRUCT_TM_TM_ZONE
             abbr = tmtime.tm_zone;
 #else
             abbr = tzname[(tmtime.tm_isdst > 0) ? 1 : 0];
 #endif
 #else
         const tm *tmtime = localtime(&t);
         if (tmtime)
 #if HAVE_STRUCT_TM_TM_ZONE
             abbr = tmtime->tm_zone;
 #else
             abbr = tzname[(tmtime->tm_isdst > 0) ? 1 : 0];
 #endif
 #endif
         KSystemTimeZoneSourcePrivate::restoreTZ();   // restore the original local time zone if necessary
     }
     return abbr;
 }
 
 QList<int> KSystemTimeZoneData::utcOffsets() const
 {
     return QList<int>();
 }