File indexing completed on 2023-09-24 04:04:56

 /*
    This file is part of the KDE libraries
    Copyright (c) 2005-2008,2011 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.
 */
 
 #include "ktimezone.h"
 
 #include <config-date.h> // SIZEOF_TIME_T
 
 #if HAVE_SYS_TIME_H
 #endif
 #if HAVE_TIME_H
 #include <time.h>
 #endif
 #include <climits>
 #include <cstdlib>
 
 #include <QDebug>
 #include <QSet>
 #include <QSharedData>
 #include <QCoreApplication>
 
 int gmtoff(time_t t);   // defined in ksystemtimezone.cpp
 
 /******************************************************************************/
 
 class KTimeZonesPrivate
 {
 public:
     KTimeZonesPrivate() {}
 
     KTimeZones::ZoneMap zones;
 };
 
 KTimeZones::KTimeZones()
     : d(new KTimeZonesPrivate)
 {
 }
 
 KTimeZones::~KTimeZones()
 {
     delete d;
 }
 
 const KTimeZones::ZoneMap KTimeZones::zones() const
 {
     return d->zones;
 }
 
 bool KTimeZones::add(const KTimeZone &zone)
 {
     if (!zone.isValid()) {
         return false;
     }
     if (d->zones.find(zone.name()) != d->zones.end()) {
         return false;    // name already exists
     }
     d->zones.insert(zone.name(), zone);
     return true;
 }
 
 KTimeZone KTimeZones::remove(const KTimeZone &zone)
 {
     if (zone.isValid()) {
         for (ZoneMap::Iterator it = d->zones.begin(), end = d->zones.end();  it != end;  ++it) {
             if (it.value() == zone) {
                 d->zones.erase(it);
                 return zone;
             }
         }
     }
     return KTimeZone();
 }
 
 KTimeZone KTimeZones::remove(const QString &name)
 {
     if (!name.isEmpty()) {
         ZoneMap::Iterator it = d->zones.find(name);
         if (it != d->zones.end()) {
             KTimeZone zone = it.value();
             d->zones.erase(it);
             return zone;
         }
     }
     return KTimeZone();
 }
 
 void KTimeZones::clear()
 {
     d->zones.clear();
 }
 
 KTimeZone KTimeZones::zone(const QString &name) const
 {
     if (!name.isEmpty()) {
         ZoneMap::ConstIterator it = d->zones.constFind(name);
         if (it != d->zones.constEnd()) {
             return it.value();
         }
         if (name == KTimeZone::utc().name()) {
             return KTimeZone::utc();
         }
     }
     return KTimeZone();    // error
 }
 
 /******************************************************************************/
 
 class KTimeZonePhasePrivate : public QSharedData
 {
 public:
     QByteArray       abbreviations;  // time zone abbreviations (zero-delimited)
     QString          comment;        // optional comment
     int              utcOffset;      // seconds to add to UTC
     bool             dst;            // true if daylight savings time
 
     KDELIBS4SUPPORT_DEPRECATED explicit KTimeZonePhasePrivate(int offset = 0, bool ds = false)
         : QSharedData(),
           utcOffset(offset),
           dst(ds)
     {}
     KTimeZonePhasePrivate(const KTimeZonePhasePrivate &rhs)
         : QSharedData(rhs),
           abbreviations(rhs.abbreviations),
           comment(rhs.comment),
           utcOffset(rhs.utcOffset),
           dst(rhs.dst)
     {}
     bool operator==(const KTimeZonePhasePrivate &rhs) const
     {
         return abbreviations == rhs.abbreviations
                &&  comment       == rhs.comment
                &&  utcOffset     == rhs.utcOffset
                &&  dst           == rhs.dst;
     }
 };
 
 KTimeZone::Phase::Phase()
     : d(new KTimeZonePhasePrivate)
 {
 }
 
 KTimeZone::Phase::Phase(int utcOffset, const QByteArray &abbrevs,
                         bool dst, const QString &cmt)
     : d(new KTimeZonePhasePrivate(utcOffset, dst))
 {
     d->abbreviations = abbrevs;
     d->comment       = cmt;
 }
 
 KTimeZone::Phase::Phase(int utcOffset, const QList<QByteArray> &abbrevs,
                         bool dst, const QString &cmt)
     : d(new KTimeZonePhasePrivate(utcOffset, dst))
 {
     for (int i = 0, end = abbrevs.count();  i < end;  ++i) {
         if (i > 0) {
             d->abbreviations += '\0';
         }
         d->abbreviations += abbrevs[i];
     }
     d->comment = cmt;
 }
 
 KTimeZone::Phase::Phase(const KTimeZone::Phase &rhs)
     : d(rhs.d)
 {
 }
 
 KTimeZone::Phase::~Phase()
 {
 }
 
 KTimeZone::Phase &KTimeZone::Phase::operator=(const KTimeZone::Phase &rhs)
 {
     d = rhs.d;
     return *this;
 }
 
 bool KTimeZone::Phase::operator==(const KTimeZone::Phase &rhs) const
 {
     return d == rhs.d  ||  *d == *rhs.d;
 }
 
 int KTimeZone::Phase::utcOffset() const
 {
     return d->utcOffset;
 }
 
 QList<QByteArray> KTimeZone::Phase::abbreviations() const
 {
     return d->abbreviations.split('\0');
 }
 
 bool KTimeZone::Phase::isDst() const
 {
     return d->dst;
 }
 
 QString KTimeZone::Phase::comment() const
 {
     return d->comment;
 }
 
 /******************************************************************************/
 
 class KTimeZoneTransitionPrivate
 {
 public:
     QDateTime time;
     KTimeZone::Phase phase;
 };
 
 KTimeZone::Transition::Transition()
     : d(new KTimeZoneTransitionPrivate)
 {
 }
 
 KTimeZone::Transition::Transition(const QDateTime &t, const KTimeZone::Phase &p)
     : d(new KTimeZoneTransitionPrivate)
 {
     d->time  = t;
     d->phase = p;
 }
 
 KTimeZone::Transition::Transition(const KTimeZone::Transition &t)
     : d(new KTimeZoneTransitionPrivate)
 {
     d->time  = t.d->time;
     d->phase = t.d->phase;
 }
 
 KTimeZone::Transition::~Transition()
 {
     delete d;
 }
 
 KTimeZone::Transition &KTimeZone::Transition::operator=(const KTimeZone::Transition &t)
 {
     d->time  = t.d->time;
     d->phase = t.d->phase;
     return *this;
 }
 
 bool KTimeZone::Transition::operator<(const KTimeZone::Transition &rhs) const
 {
     return d->time < rhs.d->time;
 }
 
 QDateTime        KTimeZone::Transition::time() const
 {
     return d->time;
 }
 KTimeZone::Phase KTimeZone::Transition::phase() const
 {
     return d->phase;
 }
 
 /******************************************************************************/
 
 class KTimeZoneDataPrivate
 {
 public:
     QList<KTimeZone::Phase>       phases;
     QList<KTimeZone::Transition>  transitions;
     QList<KTimeZone::LeapSeconds> leapChanges;
     QList<int>                    utcOffsets;
     QList<QByteArray>             abbreviations;
     KTimeZone::Phase              prePhase;    // phase to use before the first transition
 
     KTimeZoneDataPrivate() {}
     // Find the last transition before a specified UTC or local date/time.
     int transitionIndex(const QDateTime &dt) const;
     bool transitionIndexes(const QDateTime &start, const QDateTime &end, int &ixstart, int &ixend) const;
     bool isSecondOccurrence(const QDateTime &utcLocalTime, int transitionIndex) const;
 };
 
 /******************************************************************************/
 
 class KTimeZonePrivate : public QSharedData
 {
 public:
     KTimeZonePrivate() : source(nullptr), data(nullptr), refCount(1), cachedTransitionIndex(-1) {}
     KTimeZonePrivate(KTimeZoneSource *src, const QString &nam,
                      const QString &country, float lat, float lon, const QString &cmnt);
     KTimeZonePrivate(const KTimeZonePrivate &);
     ~KTimeZonePrivate()
     {
         delete data;
     }
     KTimeZonePrivate &operator=(const KTimeZonePrivate &);
     static KTimeZoneSource *utcSource();
     static void cleanup();
 
     KTimeZoneSource *source;
     QString name;
     QString countryCode;
     QString comment;
     float   latitude;
     float   longitude;
     mutable KTimeZoneData *data;
     int     refCount; // holds the number of KTimeZoneBackend instances using the KTimeZonePrivate instance as a d-pointer.
     int       cachedTransitionIndex;
     QDateTime cachedTransitionStartZoneTime;
     QDateTime cachedTransitionEndZoneTime;
     bool      cachedTransitionTimesValid;
 
 private:
     static KTimeZoneSource *mUtcSource;
 };
 
 KTimeZoneSource *KTimeZonePrivate::mUtcSource = nullptr;
 
 KTimeZonePrivate::KTimeZonePrivate(KTimeZoneSource *src, const QString &nam,
                                    const QString &country, float lat, float lon, const QString &cmnt)
     : source(src),
       name(nam),
       countryCode(country.toUpper()),
       comment(cmnt),
       latitude(lat),
       longitude(lon),
       data(nullptr),
       refCount(1),
       cachedTransitionIndex(-1)
 {
     // Detect duff values.
     if (latitude > 90 || latitude < -90) {
         latitude = KTimeZone::UNKNOWN;
     }
     if (longitude > 180 || longitude < -180) {
         longitude = KTimeZone::UNKNOWN;
     }
 }
 
 KTimeZonePrivate::KTimeZonePrivate(const KTimeZonePrivate &rhs)
     : QSharedData(rhs),
       source(rhs.source),
       name(rhs.name),
       countryCode(rhs.countryCode),
       comment(rhs.comment),
       latitude(rhs.latitude),
       longitude(rhs.longitude),
       refCount(1),
       cachedTransitionIndex(rhs.cachedTransitionIndex),
       cachedTransitionStartZoneTime(rhs.cachedTransitionStartZoneTime),
       cachedTransitionEndZoneTime(rhs.cachedTransitionEndZoneTime),
       cachedTransitionTimesValid(rhs.cachedTransitionTimesValid)
 {
     if (rhs.data) {
         data = rhs.data->clone();
     } else {
         data = nullptr;
     }
 }
 
 KTimeZonePrivate &KTimeZonePrivate::operator=(const KTimeZonePrivate &rhs)
 {
     // Changing the contents of a KTimeZonePrivate instance by means of operator=() doesn't affect how
     // many references to it are held.
     source      = rhs.source;
     name        = rhs.name;
     countryCode = rhs.countryCode;
     comment     = rhs.comment;
     latitude    = rhs.latitude;
     longitude   = rhs.longitude;
     cachedTransitionIndex         = rhs.cachedTransitionIndex;
     cachedTransitionStartZoneTime = rhs.cachedTransitionStartZoneTime;
     cachedTransitionEndZoneTime   = rhs.cachedTransitionEndZoneTime;
     cachedTransitionTimesValid    = rhs.cachedTransitionTimesValid;
     delete data;
     if (rhs.data) {
         data = rhs.data->clone();
     } else {
         data = nullptr;
     }
     // refCount is unchanged
     return *this;
 }
 
 KTimeZoneSource *KTimeZonePrivate::utcSource()
 {
     if (!mUtcSource) {
         mUtcSource = new KTimeZoneSource;
         qAddPostRoutine(KTimeZonePrivate::cleanup);
     }
     return mUtcSource;
 }
 
 void KTimeZonePrivate::cleanup()
 {
     delete mUtcSource;
 }
 
 /******************************************************************************/
 
 Q_GLOBAL_STATIC(KTimeZonePrivate, s_emptyTimeZonePrivate)
 
 KTimeZoneBackend::KTimeZoneBackend()
     : d(s_emptyTimeZonePrivate())
 {
     ++d->refCount;
 }
 
 KTimeZoneBackend::KTimeZoneBackend(const QString &name)
     : d(new KTimeZonePrivate(KTimeZonePrivate::utcSource(), name, QString(), KTimeZone::UNKNOWN, KTimeZone::UNKNOWN, QString()))
 {}
 
 KTimeZoneBackend::KTimeZoneBackend(KTimeZoneSource *source, const QString &name,
                                    const QString &countryCode, float latitude, float longitude, const QString &comment)
     : d(new KTimeZonePrivate(source, name, countryCode, latitude, longitude, comment))
 {}
 
 KTimeZoneBackend::KTimeZoneBackend(const KTimeZoneBackend &other)
     : d(other.d)
 {
     ++d->refCount;
 }
 
 KTimeZoneBackend::~KTimeZoneBackend()
 {
     if (d && --d->refCount == 0) {
         delete d;
     }
     d = nullptr;
 }
 
 KTimeZoneBackend &KTimeZoneBackend::operator=(const KTimeZoneBackend &other)
 {
     if (d != other.d) {
         if (--d->refCount == 0) {
             delete d;
         }
         d = other.d;
         ++d->refCount;
     }
     return *this;
 }
 
 QByteArray KTimeZoneBackend::type() const
 {
     return "KTimeZone";
 }
 
 KTimeZoneBackend *KTimeZoneBackend::clone() const
 {
     return new KTimeZoneBackend(*this);
 }
 
 int KTimeZoneBackend::offsetAtZoneTime(const KTimeZone *caller, const QDateTime &zoneDateTime, int *secondOffset) const
 {
     if (!zoneDateTime.isValid()  ||  zoneDateTime.timeSpec() != Qt::LocalTime) {  // check for invalid time
         if (secondOffset) {
             *secondOffset = KTimeZone::InvalidOffset;
         }
         return KTimeZone::InvalidOffset;
     }
     const QList<KTimeZone::Transition> transitions = caller->transitions();
     int index = d->cachedTransitionIndex;
     if (index >= 0 && index < transitions.count()) {
         // There is a cached transition - check whether zoneDateTime uses it.
         // Caching is used because this method has been found to consume
         // significant CPU in real life applications.
         if (!d->cachedTransitionTimesValid) {
             const int offset = transitions[index].phase().utcOffset();
             const int preoffset = (index > 0) ? transitions[index - 1].phase().utcOffset() : d->data ? d->data->previousUtcOffset() : KTimeZone::InvalidOffset;
             d->cachedTransitionStartZoneTime = transitions[index].time().addSecs(qMax(offset, preoffset));
             if (index + 1 < transitions.count()) {
                 const int postoffset = transitions[index + 1].phase().utcOffset();
                 d->cachedTransitionEndZoneTime = transitions[index + 1].time().addSecs(qMin(offset, postoffset));
             }
             d->cachedTransitionTimesValid = true;
         }
         QDateTime dtutc = zoneDateTime;
         dtutc.setTimeSpec(Qt::UTC);
         if (dtutc >= d->cachedTransitionStartZoneTime
                 && (index + 1 >= transitions.count() || dtutc < d->cachedTransitionEndZoneTime)) {
             // The time falls within the cached transition limits, so return its UTC offset
             const int offset = transitions[index].phase().utcOffset();
             if (secondOffset) {
                 *secondOffset = offset;
             }
 #ifdef COMPILING_TESTS
             // qDebug() << "-> Using cache";   // enable the debug area to see this in the tests
 #endif
             return offset;
         }
     }
 
     // The time doesn't fall within the cached transition, or there isn't a cached transition
 #ifdef COMPILING_TESTS
     // qDebug() << "-> No cache";   // enable the debug area to see this in the tests
 #endif
     bool validTime;
     int secondIndex = -1;
     index = caller->transitionIndex(zoneDateTime, (secondOffset ? &secondIndex : nullptr), &validTime);
     const KTimeZone::Transition *tr = (index >= 0) ? &transitions[index] : nullptr;
     const int offset = tr ? tr->phase().utcOffset()
                        : validTime ? (d->data ? d->data->previousUtcOffset() : KTimeZone::InvalidOffset)
                        : KTimeZone::InvalidOffset;
     if (secondOffset) {
         *secondOffset = (secondIndex >= 0) ? transitions.at(secondIndex).phase().utcOffset() : offset;
     }
 
     // Cache transition data for subsequent date/time values which occur after the same transition.
     d->cachedTransitionIndex = index;
     d->cachedTransitionTimesValid = false;
     return offset;
 }
 
 int KTimeZoneBackend::offsetAtUtc(const KTimeZone *caller, const QDateTime &utcDateTime) const
 {
     if (!utcDateTime.isValid()  ||  utcDateTime.timeSpec() != Qt::UTC) {  // check for invalid time
         return 0;
     }
     const QList<KTimeZone::Transition> transitions = caller->transitions();
     int index = d->cachedTransitionIndex;
     if (index >= 0 && index < transitions.count()) {
         // There is a cached transition - check whether utcDateTime uses it.
         if (utcDateTime >= transitions[index].time()
                 && (index + 1 >= transitions.count()
                     || utcDateTime < transitions[index + 1].time())) {
             // The time falls within the cached transition, so return its UTC offset
 #ifdef COMPILING_TESTS
             // qDebug() << "Using cache";   // enable the debug area to see this in the tests
 #endif
             return transitions[index].phase().utcOffset();
         }
     }
 
     // The time doesn't fall within the cached transition, or there isn't a cached transition
 #ifdef COMPILING_TESTS
     // qDebug() << "No cache";   // enable the debug area to see this in the tests
 #endif
     index = caller->transitionIndex(utcDateTime);
     d->cachedTransitionIndex = index;   // cache transition data
     d->cachedTransitionTimesValid = false;
     const KTimeZone::Transition *tr = (index >= 0) ? &transitions.at(index) : nullptr;
     return tr ? tr->phase().utcOffset() : (d->data ? d->data->previousUtcOffset() : KTimeZone::InvalidOffset);
 }
 
 int KTimeZoneBackend::offset(const KTimeZone *caller, time_t t) const
 {
     return offsetAtUtc(caller, KTimeZone::fromTime_t(t));
 }
 
 bool KTimeZoneBackend::isDstAtUtc(const KTimeZone *caller, const QDateTime &utcDateTime) const
 {
     if (!utcDateTime.isValid()  ||  utcDateTime.timeSpec() != Qt::UTC) {  // check for invalid time
         return false;
     }
     const KTimeZone::Transition *tr = caller->transition(utcDateTime);
     if (!tr) {
         return false;
     }
     return tr->phase().isDst();
 }
 
 bool KTimeZoneBackend::isDst(const KTimeZone *caller, time_t t) const
 {
     return isDstAtUtc(caller, KTimeZone::fromTime_t(t));
 }
 
 bool KTimeZoneBackend::hasTransitions(const KTimeZone *caller) const
 {
     Q_UNUSED(caller);
     return false;
 }
 
 /******************************************************************************/
 
 #if SIZEOF_TIME_T == 8
 const time_t KTimeZone::InvalidTime_t = 0x800000000000000LL;
 #else
 const time_t KTimeZone::InvalidTime_t = 0x80000000;
 #endif
 const int    KTimeZone::InvalidOffset = 0x80000000;
 const float  KTimeZone::UNKNOWN = 1000.0;
 
 KTimeZone::KTimeZone()
     : d(new KTimeZoneBackend())
 {}
 
 KTimeZone::KTimeZone(const QString &name)
     : d(new KTimeZoneBackend(name))
 {}
 
 KTimeZone::KTimeZone(const KTimeZone &tz)
     : d(tz.d->clone())
 {}
 
 KTimeZone::~KTimeZone()
 {
     delete d;
 }
 
 KTimeZone::KTimeZone(KTimeZoneBackend *impl)
     : d(impl)
 {
     // 'impl' should be a newly constructed object, with refCount = 1
     Q_ASSERT(d->d->refCount == 1 || d->d == s_emptyTimeZonePrivate());
 }
 
 KTimeZone &KTimeZone::operator=(const KTimeZone &tz)
 {
     if (d != tz.d) {
         delete d;
         d = tz.d->clone();
     }
     return *this;
 }
 
 bool KTimeZone::operator==(const KTimeZone &rhs) const
 {
     return d->d == rhs.d->d;
 }
 
 QByteArray KTimeZone::type() const
 {
     return d->type();
 }
 
 bool KTimeZone::isValid() const
 {
     return !d->d->name.isEmpty();
 }
 
 QString KTimeZone::countryCode() const
 {
     return d->d->countryCode;
 }
 
 float KTimeZone::latitude() const
 {
     return d->d->latitude;
 }
 
 float KTimeZone::longitude() const
 {
     return d->d->longitude;
 }
 
 QString KTimeZone::comment() const
 {
     return d->d->comment;
 }
 
 QString KTimeZone::name() const
 {
     return d->d->name;
 }
 
 QList<QByteArray> KTimeZone::abbreviations() const
 {
     if (!data(true)) {
         return QList<QByteArray>();
     }
     return d->d->data->abbreviations();
 }
 
 QByteArray KTimeZone::abbreviation(const QDateTime &utcDateTime) const
 {
     if (utcDateTime.timeSpec() != Qt::UTC  ||  !data(true)) {
         return QByteArray();
     }
     return d->d->data->abbreviation(utcDateTime);
 }
 
 QList<int> KTimeZone::utcOffsets() const
 {
     if (!data(true)) {
         return QList<int>();
     }
     return d->d->data->utcOffsets();
 }
 
 QList<KTimeZone::Phase> KTimeZone::phases() const
 {
     if (!data(true)) {
         return QList<KTimeZone::Phase>();
     }
     return d->d->data->phases();
 }
 
 bool KTimeZone::hasTransitions() const
 {
     return d->hasTransitions(this);
 }
 
 QList<KTimeZone::Transition> KTimeZone::transitions(const QDateTime &start, const QDateTime &end) const
 {
     if (!data(true)) {
         return QList<KTimeZone::Transition>();
     }
     return d->d->data->transitions(start, end);
 }
 
 const KTimeZone::Transition *KTimeZone::transition(const QDateTime &dt, const Transition **secondTransition,
         bool *validTime) const
 {
     if (!data(true)) {
         if (validTime) {
             *validTime = false;
         }
         return nullptr;
     }
     return d->d->data->transition(dt, secondTransition, validTime);
 }
 
 int KTimeZone::transitionIndex(const QDateTime &dt, int *secondIndex, bool *validTime) const
 {
     if (!data(true)) {
         if (validTime) {
             *validTime = false;
         }
         return -1;
     }
     return d->d->data->transitionIndex(dt, secondIndex, validTime);
 }
 
 QList<QDateTime> KTimeZone::transitionTimes(const Phase &phase, const QDateTime &start, const QDateTime &end) const
 {
     if (!data(true)) {
         return QList<QDateTime>();
     }
     return d->d->data->transitionTimes(phase, start, end);
 }
 
 QList<KTimeZone::LeapSeconds> KTimeZone::leapSecondChanges() const
 {
     if (!data(true)) {
         return QList<KTimeZone::LeapSeconds>();
     }
     return d->d->data->leapSecondChanges();
 }
 
 KTimeZoneSource *KTimeZone::source() const
 {
     return d->d->source;
 }
 
 const KTimeZoneData *KTimeZone::data(bool create) const
 {
     if (!isValid()) {
         return nullptr;
     }
     if (create && !d->d->data && d->d->source->useZoneParse()) {
         d->d->data = d->d->source->parse(*this);
     }
     return d->d->data;
 }
 
 void KTimeZone::setData(KTimeZoneData *data, KTimeZoneSource *source)
 {
     if (!isValid()) {
         return;
     }
     delete d->d->data;
     d->d->data = data;
     if (source) {
         d->d->source = source;
     }
 }
 
 bool KTimeZone::updateBase(const KTimeZone &other)
 {
     if (d->d->name.isEmpty() || d->d->name != other.d->d->name) {
         return false;
     }
     d->d->countryCode = other.d->d->countryCode;
     d->d->comment     = other.d->d->comment;
     d->d->latitude    = other.d->d->latitude;
     d->d->longitude   = other.d->d->longitude;
     return true;
 }
 
 bool KTimeZone::parse() const
 {
     if (!isValid()) {
         return false;
     }
     if (d->d->source->useZoneParse()) {
         delete d->d->data;
         d->d->data = d->d->source->parse(*this);
     }
     return d->d->data;
 }
 
 QDateTime KTimeZone::toUtc(const QDateTime &zoneDateTime) const
 {
     if (!zoneDateTime.isValid()  ||  zoneDateTime.timeSpec() != Qt::LocalTime) {
         return QDateTime();
     }
     const int secs = offsetAtZoneTime(zoneDateTime);
     if (secs == InvalidOffset) {
         return QDateTime();
     }
     QDateTime dt = zoneDateTime;
     dt.setTimeSpec(Qt::UTC);
     return dt.addSecs(-secs);
 }
 
 QDateTime KTimeZone::toZoneTime(const QDateTime &utcDateTime, bool *secondOccurrence) const
 {
     if (secondOccurrence) {
         *secondOccurrence = false;
     }
     if (!utcDateTime.isValid()  ||  utcDateTime.timeSpec() != Qt::UTC) {  // check for invalid time
         return QDateTime();
     }
 
     // Convert UTC to local time
     if (hasTransitions()) {
         if (!data(true)) {
             // No data - default to UTC
             QDateTime dt = utcDateTime;
             dt.setTimeSpec(Qt::LocalTime);
             return dt;
         }
 
         const KTimeZoneData *data = d->d->data;
         const int index = data->transitionIndex(utcDateTime);
         const int secs = (index >= 0) ? data->transitions().at(index).phase().utcOffset() : data->previousUtcOffset();
         QDateTime dt = utcDateTime.addSecs(secs);
         if (secondOccurrence) {
             // Check whether the local time occurs twice around a daylight savings time
             // shift, and if so, whether it's the first or second occurrence.
             *secondOccurrence = data->d->isSecondOccurrence(dt, index);
         }
         dt.setTimeSpec(Qt::LocalTime);
         return dt;
     } else {
         const int secs = offsetAtUtc(utcDateTime);
         QDateTime dt = utcDateTime.addSecs(secs);
         dt.setTimeSpec(Qt::LocalTime);
         if (secondOccurrence) {
             // Check whether the local time occurs twice around a daylight savings time
             // shift, and if so, whether it's the first or second occurrence.
             *secondOccurrence = (secs != offsetAtZoneTime(dt));
         }
         return dt;
     }
 }
 
 QDateTime KTimeZone::convert(const KTimeZone &newZone, const QDateTime &zoneDateTime) const
 {
     if (newZone == *this) {
         if (zoneDateTime.timeSpec() != Qt::LocalTime) {
             return QDateTime();
         }
         return zoneDateTime;
     }
     return newZone.toZoneTime(toUtc(zoneDateTime));
 }
 
 int KTimeZone::offsetAtZoneTime(const QDateTime &zoneDateTime, int *secondOffset) const
 {
     return d->offsetAtZoneTime(this, zoneDateTime, secondOffset);
 }
 
 int KTimeZone::offsetAtUtc(const QDateTime &utcDateTime) const
 {
     return d->offsetAtUtc(this, utcDateTime);
 }
 
 int KTimeZone::offset(time_t t) const
 {
     return d->offset(this, t);
 }
 
 int KTimeZone::currentOffset(Qt::TimeSpec basis) const
 {
     // Get current offset of this time zone to UTC
     const time_t now = time(nullptr);
     const int secs = offset(now);
 
     switch (basis) {
     case Qt::LocalTime:
         // Return the current offset of this time zone to the local system time
         return secs - gmtoff(now);
     case Qt::UTC:
         // Return the current offset of this time zone to UTC
         return secs;
 
     default:
         break;
     }
     return 0;
 }
 
 bool KTimeZone::isDstAtUtc(const QDateTime &utcDateTime) const
 {
     return d->isDstAtUtc(this, utcDateTime);
 }
 
 bool KTimeZone::isDst(time_t t) const
 {
     return d->isDst(this, t);
 }
 
 KTimeZone KTimeZone::utc()
 {
     static KTimeZone utcZone(QLatin1String("UTC"));
     return utcZone;
 }
 
 QDateTime KTimeZone::fromTime_t(time_t t)
 {
     static const int secondsADay = 86400;
     static const QDate epochDate(1970, 1, 1);
     static const QTime epochTime(0, 0, 0);
     int days = t / secondsADay;
     int secs;
     if (t >= 0) {
         secs = t % secondsADay;
     } else {
         secs = secondsADay - (-t % secondsADay);
         --days;
     }
     return QDateTime(epochDate.addDays(days), epochTime.addSecs(secs), Qt::UTC);
 }
 
 time_t KTimeZone::toTime_t(const QDateTime &utcDateTime)
 {
     static const QDate epochDate(1970, 1, 1);
     static const QTime epochTime(0, 0, 0);
     if (utcDateTime.timeSpec() != Qt::UTC) {
         return InvalidTime_t;
     }
     const qint64 days = epochDate.daysTo(utcDateTime.date());
     const qint64 secs = epochTime.secsTo(utcDateTime.time());
     const qint64 t64 = days * 86400 + secs;
     const time_t t = static_cast<time_t>(t64);
     if (static_cast<qint64>(t) != t64) {
         return InvalidTime_t;
     }
     return t;
 }
 
 /******************************************************************************/
 
 class KTimeZoneSourcePrivate
 {
 public:
     bool mUseZoneParse;
 };
 
 KTimeZoneSource::KTimeZoneSource()
     : d(new KTimeZoneSourcePrivate)
 {
     d->mUseZoneParse = true;
 }
 
 KTimeZoneSource::KTimeZoneSource(bool useZoneParse)
     : d(new KTimeZoneSourcePrivate)
 {
     d->mUseZoneParse = useZoneParse;
 }
 
 KTimeZoneSource::~KTimeZoneSource()
 {
     delete d;
 }
 
 KTimeZoneData *KTimeZoneSource::parse(const KTimeZone &) const
 {
     Q_ASSERT(d->mUseZoneParse);  // method should never be called if it isn't usable
     return new KTimeZoneData;
 }
 
 bool KTimeZoneSource::useZoneParse() const
 {
     return d->mUseZoneParse;
 }
 
 /******************************************************************************/
 
 class KTimeZoneLeapSecondsPrivate
 {
 public:
     QDateTime  dt;         // UTC time when this change occurred
     QString    comment;    // optional comment
     int        seconds;    // number of leap seconds
 };
 
 KTimeZone::LeapSeconds::LeapSeconds()
     : d(new KTimeZoneLeapSecondsPrivate)
 {
 }
 
 KTimeZone::LeapSeconds::LeapSeconds(const QDateTime &utc, int leap, const QString &cmt)
     : d(new KTimeZoneLeapSecondsPrivate)
 {
     if (utc.timeSpec() == Qt::UTC) { // invalid if start time is not UTC
         d->dt      = utc;
         d->comment = cmt;
         d->seconds = leap;
     }
 }
 
 KTimeZone::LeapSeconds::LeapSeconds(const KTimeZone::LeapSeconds &c)
     : d(new KTimeZoneLeapSecondsPrivate)
 {
     d->dt      = c.d->dt;
     d->comment = c.d->comment;
     d->seconds = c.d->seconds;
 }
 
 KTimeZone::LeapSeconds::~LeapSeconds()
 {
     delete d;
 }
 
 KTimeZone::LeapSeconds &KTimeZone::LeapSeconds::operator=(const KTimeZone::LeapSeconds &c)
 {
     d->dt      = c.d->dt;
     d->comment = c.d->comment;
     d->seconds = c.d->seconds;
     return *this;
 }
 
 bool KTimeZone::LeapSeconds::operator<(const KTimeZone::LeapSeconds &c) const
 {
     return d->dt < c.d->dt;
 }
 
 QDateTime KTimeZone::LeapSeconds::dateTime() const
 {
     return d->dt;
 }
 
 bool KTimeZone::LeapSeconds::isValid() const
 {
     return d->dt.isValid();
 }
 
 int KTimeZone::LeapSeconds::leapSeconds() const
 {
     return d->seconds;
 }
 
 QString KTimeZone::LeapSeconds::comment() const
 {
     return d->comment;
 }
 
 /******************************************************************************/
 
 int KTimeZoneDataPrivate::transitionIndex(const QDateTime &dt) const
 {
     // Do a binary search to find the last transition before this date/time
     int start = -1;
     int end = transitions.count();
     if (dt.timeSpec() == Qt::UTC) {
         while (end - start > 1) {
             int i = (start + end) / 2;
             if (dt < transitions[i].time()) {
                 end = i;
             } else {
                 start = i;
             }
         }
     } else {
         QDateTime dtutc = dt;
         dtutc.setTimeSpec(Qt::UTC);
         while (end - start > 1) {
             const int i = (start + end) / 2;
             if (dtutc.addSecs(-transitions[i].phase().utcOffset()) < transitions[i].time()) {
                 end = i;
             } else {
                 start = i;
             }
         }
     }
     return end ? start : -1;
 }
 
 // Find the indexes to the transitions at or after start, and before or at end.
 // start and end must be UTC.
 // Reply = false if none.
 bool KTimeZoneDataPrivate::transitionIndexes(const QDateTime &start, const QDateTime &end, int &ixstart, int &ixend) const
 {
     ixstart = 0;
     if (start.isValid() && start.timeSpec() == Qt::UTC) {
         ixstart = transitionIndex(start);
         if (ixstart < 0) {
             ixstart = 0;
         } else if (transitions[ixstart].time() < start) {
             if (++ixstart >= transitions.count()) {
                 return false;    // there are no transitions at/after 'start'
             }
         }
     }
     ixend = -1;
     if (end.isValid() && end.timeSpec() == Qt::UTC) {
         ixend = transitionIndex(end);
         if (ixend < 0) {
             return false;    // there are no transitions at/before 'end'
         }
     }
     return true;
 }
 
 /* Check if it's a local time which occurs both before and after the specified
  * transition (for which it has to span a daylight saving to standard time change).
  * @param utcLocalTime local time set to Qt::UTC
  */
 bool KTimeZoneDataPrivate::isSecondOccurrence(const QDateTime &utcLocalTime, int transitionIndex) const
 {
     if (transitionIndex < 0) {
         return false;
     }
     const int offset = transitions[transitionIndex].phase().utcOffset();
     const int prevoffset = (transitionIndex > 0) ? transitions[transitionIndex - 1].phase().utcOffset() : prePhase.utcOffset();
     const int phaseDiff = prevoffset - offset;
     if (phaseDiff <= 0) {
         return false;
     }
     // Find how long after the start of the latest phase 'dt' is
     const qint64 afterStart = transitions[transitionIndex].time().msecsTo(utcLocalTime)/1000 - offset;
     return (afterStart < phaseDiff);
 }
 
 KTimeZoneData::KTimeZoneData()
     : d(new KTimeZoneDataPrivate)
 { }
 
 KTimeZoneData::KTimeZoneData(const KTimeZoneData &c)
     : d(new KTimeZoneDataPrivate)
 {
     d->phases        = c.d->phases;
     d->transitions   = c.d->transitions;
     d->leapChanges   = c.d->leapChanges;
     d->utcOffsets    = c.d->utcOffsets;
     d->abbreviations = c.d->abbreviations;
     d->prePhase      = c.d->prePhase;
 }
 
 KTimeZoneData::~KTimeZoneData()
 {
     delete d;
 }
 
 KTimeZoneData &KTimeZoneData::operator=(const KTimeZoneData &c)
 {
     d->phases        = c.d->phases;
     d->transitions   = c.d->transitions;
     d->leapChanges   = c.d->leapChanges;
     d->utcOffsets    = c.d->utcOffsets;
     d->abbreviations = c.d->abbreviations;
     d->prePhase      = c.d->prePhase;
     return *this;
 }
 
 KTimeZoneData *KTimeZoneData::clone() const
 {
     return new KTimeZoneData(*this);
 }
 
 QList<QByteArray> KTimeZoneData::abbreviations() const
 {
     if (d->abbreviations.isEmpty()) {
         for (int i = 0, end = d->phases.count();  i < end;  ++i) {
             const QList<QByteArray> abbrevs = d->phases[i].abbreviations();
             for (int j = 0, jend = abbrevs.count();  j < jend;  ++j)
                 if (!d->abbreviations.contains(abbrevs[j])) {
                     d->abbreviations.append(abbrevs[j]);
                 }
         }
         if (d->abbreviations.isEmpty()) {
             d->abbreviations += "UTC";
         }
     }
     return d->abbreviations;
 }
 
 QByteArray KTimeZoneData::abbreviation(const QDateTime &utcDateTime) const
 {
     if (d->phases.isEmpty()) {
         return "UTC";
     }
     const KTimeZone::Transition *tr = transition(utcDateTime);
     const QList<QByteArray> abbrevs = tr ? tr->phase().abbreviations()
                                       : d->prePhase.abbreviations();
     if (abbrevs.isEmpty()) {
         return QByteArray();
     }
     return abbrevs[0];
 }
 
 QList<int> KTimeZoneData::utcOffsets() const
 {
     if (d->utcOffsets.isEmpty()) {
         for (int i = 0, end = d->phases.count();  i < end;  ++i) {
             const int offset = d->phases[i].utcOffset();
             if (!d->utcOffsets.contains(offset)) {
                 d->utcOffsets.append(offset);
             }
         }
         if (d->utcOffsets.isEmpty()) {
             d->utcOffsets += 0;
         } else {
             std::sort(d->utcOffsets.begin(), d->utcOffsets.end());
         }
     }
     return d->utcOffsets;
 }
 
 QList<KTimeZone::Phase> KTimeZoneData::phases() const
 {
     return d->phases;
 }
 
 void KTimeZoneData::setPhases(const QList<KTimeZone::Phase> &phases, const KTimeZone::Phase &previousPhase)
 {
     d->phases   = phases;
     d->prePhase = previousPhase;
 }
 
 void KTimeZoneData::setPhases(const QList<KTimeZone::Phase> &phases, int previousUtcOffset)
 {
     d->phases   = phases;
     d->prePhase = KTimeZone::Phase(previousUtcOffset, QByteArray(), false);
 }
 
 bool KTimeZoneData::hasTransitions() const
 {
     return false;
 }
 
 QList<KTimeZone::Transition> KTimeZoneData::transitions(const QDateTime &start, const QDateTime &end) const
 {
     int ixstart, ixend;
     if (!d->transitionIndexes(start, end, ixstart, ixend)) {
         return QList<KTimeZone::Transition>();    // there are no transitions within the time period
     }
     if (ixend >= 0) {
         return d->transitions.mid(ixstart, ixend - ixstart + 1);
     }
     if (ixstart > 0) {
         return d->transitions.mid(ixstart);
     }
     return d->transitions;
 }
 
 void KTimeZoneData::setTransitions(const QList<KTimeZone::Transition> &transitions)
 {
     d->transitions = transitions;
 }
 
 int KTimeZoneData::previousUtcOffset() const
 {
     return d->prePhase.utcOffset();
 }
 
 const KTimeZone::Transition *KTimeZoneData::transition(const QDateTime &dt, const KTimeZone::Transition **secondTransition,
         bool *validTime) const
 {
     int secondIndex;
     const int index = transitionIndex(dt, (secondTransition ? &secondIndex : nullptr), validTime);
     if (secondTransition) {
         *secondTransition = (secondIndex >= 0) ? &d->transitions[secondIndex] : nullptr;
     }
     return (index >= 0) ? &d->transitions[index] : nullptr;
 }
 
 int KTimeZoneData::transitionIndex(const QDateTime &dt, int *secondIndex, bool *validTime) const
 {
     if (validTime) {
         *validTime = true;
     }
 
     // Find the last transition before this date/time
     int index = d->transitionIndex(dt);
     if (dt.timeSpec() == Qt::UTC) {
         if (secondIndex) {
             *secondIndex = index;
         }
         return index;
     } else {
         /* Check whether the specified local time actually occurs.
          * Find the start of the next phase, and check if it falls in the gap
          * between the two phases.
          */
         QDateTime dtutc = dt;
         dtutc.setTimeSpec(Qt::UTC);
         const int count = d->transitions.count();
         const int next = (index >= 0) ? index + 1 : 0;
         if (next < count) {
             KTimeZone::Phase nextPhase = d->transitions.at(next).phase();
             const int offset = (index >= 0) ? d->transitions.at(index).phase().utcOffset() : d->prePhase.utcOffset();
             const int phaseDiff = nextPhase.utcOffset() - offset;
             if (phaseDiff > 0) {
                 // Get UTC equivalent as if 'dt' was in the next phase
                 if (dtutc.msecsTo(d->transitions.at(next).time())/1000 + nextPhase.utcOffset() <= phaseDiff) {
                     // The time falls in the gap between the two phases,
                     // so return an invalid value.
                     if (validTime) {
                         *validTime = false;
                     }
                     if (secondIndex) {
                         *secondIndex = -1;
                     }
                     return -1;
                 }
             }
         }
 
         if (index < 0) {
             // The specified time is before the first phase
             if (secondIndex) {
                 *secondIndex = -1;
             }
             return -1;
         }
 
         /* Check if it's a local time which occurs both before and after the 'latest'
          * phase start time (for which it has to span a daylight saving to standard
          * time change).
          */
         bool duplicate = true;
         if (d->isSecondOccurrence(dtutc, index)) {
             // 'dt' occurs twice
             if (secondIndex) {
                 *secondIndex = index;
                 duplicate = false;
             }
             // Get the transition containing the first occurrence of 'dt'
             if (index <= 0) {
                 return -1;    // first occurrence of 'dt' is just before the first transition
             }
             --index;
         }
 
         if (secondIndex  &&  duplicate) {
             *secondIndex = index;
         }
         return index;
     }
 }
 
 QList<QDateTime> KTimeZoneData::transitionTimes(const KTimeZone::Phase &phase, const QDateTime &start, const QDateTime &end) const
 {
     QList<QDateTime> times;
     int ixstart, ixend;
     if (d->transitionIndexes(start, end, ixstart, ixend)) {
         if (ixend < 0) {
             ixend = d->transitions.count() - 1;
         }
         while (ixstart <= ixend) {
             if (d->transitions[ixstart].phase() == phase) {
                 times += d->transitions[ixstart].time();
             }
         }
     }
     return times;
 }
 
 QList<KTimeZone::LeapSeconds> KTimeZoneData::leapSecondChanges() const
 {
     return d->leapChanges;
 }
 
 void KTimeZoneData::setLeapSecondChanges(const QList<KTimeZone::LeapSeconds> &adjusts)
 {
     d->leapChanges = adjusts;
 }
 
 KTimeZone::LeapSeconds KTimeZoneData::leapSecondChange(const QDateTime &utc) const
 {
     if (utc.timeSpec() != Qt::UTC) {
         qCritical() << "KTimeZoneData::leapSecondChange(): non-UTC time specified" << endl;
     } else {
         for (int i = d->leapChanges.count();  --i >= 0;) {
             if (d->leapChanges[i].dateTime() < utc) {
                 return d->leapChanges[i];
             }
         }
     }
     return KTimeZone::LeapSeconds();
 }