Merge remote-tracking branch 'origin/5.13' into dev

 Conflicts:
	mkspecs/win32-clang-msvc/qmake.conf
	src/gui/image/qpnghandler.cpp

Change-Id: Ied79d02912ffb3a307a99483df7db08c7f9d0cd8

1 files changed, 33 insertions, 22 deletions

diff --git a/src/corelib/tools/qtimezoneprivate_tz.cpp b/src/corelib/tools/qtimezoneprivate_tz.cpp
index 6105c93a23..fab0b2cbf1 100644
--- a/src/corelib/tools/qtimezoneprivate_tz.cpp
+++ b/src/corelib/tools/qtimezoneprivate_tz.cpp
@@ -39,6 +39,7 @@
 
 #include "qtimezone.h"
 #include "qtimezoneprivate_p.h"
+#include "qdatetime_p.h" // ### Qt 5.14: remove once YearRange is on QDateTime
 
 #include <QtCore/QFile>
 #include <QtCore/QHash>
@@ -520,19 +521,14 @@ PosixZone PosixZone::parse(const char *&pos, const char *end)
 
 static QVector<QTimeZonePrivate::Data> calculatePosixTransitions(const QByteArray &posixRule,
                                                                  int startYear, int endYear,
-                                                                 int lastTranMSecs)
+                                                                 qint64 lastTranMSecs)
 {
     QVector<QTimeZonePrivate::Data> result;
 
-    // Limit year by qint64 max size for msecs
-    if (startYear > 292278994)
-        startYear = 292278994;
-    if (endYear > 292278994)
-        endYear = 292278994;
-
     // POSIX Format is like "TZ=CST6CDT,M3.2.0/2:00:00,M11.1.0/2:00:00"
     // i.e. "std offset dst [offset],start[/time],end[/time]"
-    // See the section about TZ at http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap08.html
+    // See the section about TZ at
+    // http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap08.html
     QList<QByteArray> parts = posixRule.split(',');
 
     PosixZone stdZone, dstZone = PosixZone::invalid();
@@ -583,6 +579,13 @@ static QVector<QTimeZonePrivate::Data> calculatePosixTransitions(const QByteArra
     else
         stdTime = QTime(2, 0, 0);
 
+    // Limit year to the range QDateTime can represent:
+    const int minYear = int(QDateTimePrivate::YearRange::First);
+    const int maxYear = int(QDateTimePrivate::YearRange::Last);
+    startYear = qBound(minYear, startYear, maxYear);
+    endYear = qBound(minYear, endYear, maxYear);
+    Q_ASSERT(startYear <= endYear);
+
     for (int year = startYear; year <= endYear; ++year) {
         QTimeZonePrivate::Data dstData;
         QDateTime dst(calculatePosixDate(dstDateRule, year), dstTime, Qt::UTC);
@@ -598,13 +601,16 @@ static QVector<QTimeZonePrivate::Data> calculatePosixTransitions(const QByteArra
         stdData.standardTimeOffset = stdZone.offset;
         stdData.daylightTimeOffset = 0;
         stdData.abbreviation = stdZone.name;
-        // Part of the high year will overflow
-        if (year == 292278994 && (dstData.atMSecsSinceEpoch < 0 || stdData.atMSecsSinceEpoch < 0)) {
+        // Part of maxYear will overflow (likewise for minYear, below):
+        if (year == maxYear && (dstData.atMSecsSinceEpoch < 0 || stdData.atMSecsSinceEpoch < 0)) {
             if (dstData.atMSecsSinceEpoch > 0) {
                 result << dstData;
             } else if (stdData.atMSecsSinceEpoch > 0) {
                 result << stdData;
             }
+        } else if (year < 1970) { // We ignore DST before the epoch.
+            if (year > minYear || stdData.atMSecsSinceEpoch != QTimeZonePrivate::invalidMSecs())
+                result << stdData;
         } else if (dst < std) {
             result << dstData << stdData;
         } else {
@@ -794,6 +800,8 @@ void QTzTimeZonePrivate::init(const QByteArray &ianaId)
         tran.atMSecsSinceEpoch = tz_tran.tz_time * 1000;
         m_tranTimes.append(tran);
     }
+    if (m_tranTimes.isEmpty() && m_posixRule.isEmpty())
+        return; // Invalid after all !
 
     if (ianaId.isEmpty())
         m_id = systemTimeZoneId();
@@ -954,22 +962,25 @@ QVector<QTimeZonePrivate::Data> QTzTimeZonePrivate::getPosixTransitions(qint64 m
 QTimeZonePrivate::Data QTzTimeZonePrivate::data(qint64 forMSecsSinceEpoch) const
 {
     // If the required time is after the last transition (or there were none)
-    // and we have a POSIX rule then use it:
-    if ((m_tranTimes.isEmpty() || m_tranTimes.last().atMSecsSinceEpoch < forMSecsSinceEpoch)
-        && !m_posixRule.isEmpty() && forMSecsSinceEpoch >= 0) {
+    // and we have a POSIX rule, then use it:
+    if (!m_posixRule.isEmpty()
+        && (m_tranTimes.isEmpty() || m_tranTimes.last().atMSecsSinceEpoch < forMSecsSinceEpoch)) {
         QVector<QTimeZonePrivate::Data> posixTrans = getPosixTransitions(forMSecsSinceEpoch);
         auto it = std::partition_point(posixTrans.cbegin(), posixTrans.cend(),
                                        [forMSecsSinceEpoch] (const QTimeZonePrivate::Data &at) {
                                            return at.atMSecsSinceEpoch <= forMSecsSinceEpoch;
                                        });
-        if (it > posixTrans.cbegin()) {
-            QTimeZonePrivate::Data data = *--it;
+        // Use most recent, if any in the past; or the first if we have no other rules:
+        if (it > posixTrans.cbegin() || (m_tranTimes.isEmpty() && it < posixTrans.cend())) {
+            QTimeZonePrivate::Data data = *(it > posixTrans.cbegin() ? it - 1 : it);
             data.atMSecsSinceEpoch = forMSecsSinceEpoch;
             return data;
         }
     }
+    if (m_tranTimes.isEmpty()) // Only possible if !isValid()
+        return invalidData();
 
-    // Otherwise, if we can find a valid tran, then use its rule:
+    // Otherwise, use the rule for the most recent or first transition:
     auto last = std::partition_point(m_tranTimes.cbegin(), m_tranTimes.cend(),
                                      [forMSecsSinceEpoch] (const QTzTransitionTime &at) {
                                          return at.atMSecsSinceEpoch <= forMSecsSinceEpoch;
@@ -989,9 +1000,9 @@ bool QTzTimeZonePrivate::hasTransitions() const
 QTimeZonePrivate::Data QTzTimeZonePrivate::nextTransition(qint64 afterMSecsSinceEpoch) const
 {
     // If the required time is after the last transition (or there were none)
-    // and we have a POSIX rule then use it:
-    if ((m_tranTimes.isEmpty() || m_tranTimes.last().atMSecsSinceEpoch < afterMSecsSinceEpoch)
-        && !m_posixRule.isEmpty() && afterMSecsSinceEpoch >= 0) {
+    // and we have a POSIX rule, then use it:
+    if (!m_posixRule.isEmpty()
+        && (m_tranTimes.isEmpty() || m_tranTimes.last().atMSecsSinceEpoch < afterMSecsSinceEpoch)) {
         QVector<QTimeZonePrivate::Data> posixTrans = getPosixTransitions(afterMSecsSinceEpoch);
         auto it = std::partition_point(posixTrans.cbegin(), posixTrans.cend(),
                                        [afterMSecsSinceEpoch] (const QTimeZonePrivate::Data &at) {
@@ -1012,9 +1023,9 @@ QTimeZonePrivate::Data QTzTimeZonePrivate::nextTransition(qint64 afterMSecsSince
 QTimeZonePrivate::Data QTzTimeZonePrivate::previousTransition(qint64 beforeMSecsSinceEpoch) const
 {
     // If the required time is after the last transition (or there were none)
-    // and we have a POSIX rule then use it:
-    if ((m_tranTimes.isEmpty() || m_tranTimes.last().atMSecsSinceEpoch < beforeMSecsSinceEpoch)
-        && !m_posixRule.isEmpty() && beforeMSecsSinceEpoch > 0) {
+    // and we have a POSIX rule, then use it:
+    if (!m_posixRule.isEmpty()
+        && (m_tranTimes.isEmpty() || m_tranTimes.last().atMSecsSinceEpoch < beforeMSecsSinceEpoch)) {
         QVector<QTimeZonePrivate::Data> posixTrans = getPosixTransitions(beforeMSecsSinceEpoch);
         auto it = std::partition_point(posixTrans.cbegin(), posixTrans.cend(),
                                        [beforeMSecsSinceEpoch] (const QTimeZonePrivate::Data &at) {