Merge "Merge remote-tracking branch 'origin/5.14' into dev"

9 files changed, 187 insertions, 114 deletions

diff --git a/src/corelib/io/qfileinfo.cpp b/src/corelib/io/qfileinfo.cpp
index b720966d8f..a6f8b45ea3 100644
--- a/src/corelib/io/qfileinfo.cpp
+++ b/src/corelib/io/qfileinfo.cpp
@@ -311,19 +311,6 @@ QDateTime &QFileInfoPrivate::getFileTime(QAbstractFileEngine::FileTime request)
 */
 
 /*!
-    \enum QFileInfo::FileType
-
-    This enum is returned by type() to describe the type of the file system
-    entity described by the QFileInfo object.
-
-    \value Unknown      The object refers to an unknown item.
-    \value Regular      The object refers to a regular file.
-    \value Directory    The object refers to a directory.
-    \value SymbolicLink The object refers to a symbolic link.
-    \value Shortcut     The object refers to a shortcut.
-*/
-
-/*!
     \fn QFileInfo &QFileInfo::operator=(QFileInfo &&other)
 
     Move-assigns \a other to this QFileInfo instance.
@@ -1008,7 +995,11 @@ bool QFileInfo::isNativePath() const
 */
 bool QFileInfo::isFile() const
 {
-    return (type() & FileTypeMask) == Regular;
+    Q_D(const QFileInfo);
+    return d->checkAttribute<bool>(
+                QFileSystemMetaData::FileType,
+                [d]() { return d->metaData.isFile(); },
+                [d]() { return d->getFileFlags(QAbstractFileEngine::FileType); });
 }
 
 /*!
@@ -1019,7 +1010,11 @@ bool QFileInfo::isFile() const
 */
 bool QFileInfo::isDir() const
 {
-    return (type() & FileTypeMask) == Directory;
+    Q_D(const QFileInfo);
+    return d->checkAttribute<bool>(
+                QFileSystemMetaData::DirectoryType,
+                [d]() { return d->metaData.isDirectory(); },
+                [d]() { return d->getFileFlags(QAbstractFileEngine::DirectoryType); });
 }
 
 
@@ -1070,8 +1065,6 @@ bool QFileInfo::isSymLink() const
 }
 
 /*!
-    \fn bool QFileInfo::isSymbolicLink() const
-
     Returns \c true if this object points to a symbolic link;
     otherwise returns \c false.
 
@@ -1091,9 +1084,16 @@ bool QFileInfo::isSymLink() const
     \sa isFile(), isDir(), isShortcut(), symLinkTarget()
 */
 
-/*!
-    \fn bool QFileInfo::isShortcut() const
+bool QFileInfo::isSymbolicLink() const
+{
+    Q_D(const QFileInfo);
+    return d->checkAttribute<bool>(
+                QFileSystemMetaData::LegacyLinkType,
+                [d]() { return d->metaData.isLink(); },
+                [d]() { return d->getFileFlags(QAbstractFileEngine::LinkType); });
+}
 
+/*!
     Returns \c true if this object points to a shortcut;
     otherwise returns \c false.
 
@@ -1110,6 +1110,14 @@ bool QFileInfo::isSymLink() const
 
     \sa isFile(), isDir(), isSymbolicLink(), symLinkTarget()
 */
+bool QFileInfo::isShortcut() const
+{
+    Q_D(const QFileInfo);
+    return d->checkAttribute<bool>(
+            QFileSystemMetaData::LegacyLinkType,
+            [d]() { return d->metaData.isLnkFile(); },
+            [d]() { return d->getFileFlags(QAbstractFileEngine::LinkType); });
+}
 
 /*!
     Returns \c true if the object points to a directory or to a symbolic
@@ -1314,53 +1322,6 @@ qint64 QFileInfo::size() const
         });
 }
 
-/*!
-    Returns the QFileInfo::FileTypes.
-
-    QFileInfo::FileTypes combines with an indirection flag (link type) and a
-    base type it refers to.
-
-    For example, \c SymbolicLink combines with \c Regular meaning a symlink to
-    a regular file.
-
-    In addition, FileTypeMask and LinkTypeMask are used to extract the base
-    type and link type respectively.
-
-    \sa isFile(), isDir(), isShortcut(), isSymbolicLink()
-*/
-QFileInfo::FileTypes QFileInfo::type() const
-{
-    Q_D(const QFileInfo);
-
-    QFileInfo::FileTypes type = QFileInfo::Unknown;
-    if (d->checkAttribute<bool>(
-            QFileSystemMetaData::LegacyLinkType,
-            [d]() { return d->metaData.isLnkFile(); },
-            [d]() { return d->getFileFlags(QAbstractFileEngine::LinkType); })) {
-        type = QFileInfo::Shortcut;
-    } else if (d->checkAttribute<bool>(
-            QFileSystemMetaData::LegacyLinkType,
-            [d]() { return d->metaData.isLink(); },
-            [d]() { return d->getFileFlags(QAbstractFileEngine::LinkType); })) {
-        type = QFileInfo::SymbolicLink;
-    }
-
-    if (d->checkAttribute<bool>(
-            QFileSystemMetaData::DirectoryType,
-            [d]() { return d->metaData.isDirectory(); },
-            [d]() { return d->getFileFlags(QAbstractFileEngine::DirectoryType); })) {
-        return type | QFileInfo::Directory;
-    }
-
-    if (d->checkAttribute<bool>(
-            QFileSystemMetaData::FileType,
-            [d]() { return d->metaData.isFile(); },
-            [d]() { return d->getFileFlags(QAbstractFileEngine::FileType); })) {
-        return type | QFileInfo::Regular;
-    }
-    return type;
-}
-
 #if QT_DEPRECATED_SINCE(5, 10)
 /*!
     \deprecated
diff --git a/src/corelib/io/qfileinfo.h b/src/corelib/io/qfileinfo.h
index 1cbeafdd4a..3ac028085a 100644
--- a/src/corelib/io/qfileinfo.h
+++ b/src/corelib/io/qfileinfo.h
@@ -66,20 +66,6 @@ public:
     QFileInfo(const QFileInfo &fileinfo);
     ~QFileInfo();
 
-    enum FileType {
-        Unknown,
-        // base type
-        Regular,
-        Directory,
-        // indirection flag
-        SymbolicLink = 0x10,
-        Shortcut     = 0x20,
-        // mask
-        FileTypeMask = 0x0f,
-        LinkTypeMask = 0xf0
-    };
-    Q_DECLARE_FLAGS(FileTypes, FileType)
-
     QFileInfo &operator=(const QFileInfo &fileinfo);
     QFileInfo &operator=(QFileInfo &&other) noexcept { swap(other); return *this; }
 
@@ -125,8 +111,8 @@ public:
     bool isFile() const;
     bool isDir() const;
     bool isSymLink() const;
-    inline bool isSymbolicLink() const  { return type() & SymbolicLink; }
-    inline bool isShortcut() const  { return type() & Shortcut; }
+    bool isSymbolicLink() const;
+    bool isShortcut() const;
     bool isRoot() const;
     bool isBundle() const;
 
@@ -145,7 +131,6 @@ public:
     QFile::Permissions permissions() const;
 
     qint64 size() const;
-    FileTypes type() const;
 
     // ### Qt6: inline these functions
 #if QT_DEPRECATED_SINCE(5, 10)
diff --git a/src/corelib/text/qlocale_win.cpp b/src/corelib/text/qlocale_win.cpp
index dc904ad02d..79ea67f966 100644
--- a/src/corelib/text/qlocale_win.cpp
+++ b/src/corelib/text/qlocale_win.cpp
@@ -116,8 +116,8 @@ struct QSystemLocalePrivate
     QVariant dateTimeFormat(QLocale::FormatType);
     QVariant dayName(int, QLocale::FormatType);
     QVariant monthName(int, QLocale::FormatType);
-    QVariant toString(const QDate &, QLocale::FormatType);
-    QVariant toString(const QTime &, QLocale::FormatType);
+    QVariant toString(QDate, QLocale::FormatType);
+    QVariant toString(QTime, QLocale::FormatType);
     QVariant toString(const QDateTime &, QLocale::FormatType);
     QVariant measurementSystem();
     QVariant collation();
@@ -394,7 +394,7 @@ QVariant QSystemLocalePrivate::monthName(int month, QLocale::FormatType type)
     return getLocaleInfo(lctype);
 }
 
-QVariant QSystemLocalePrivate::toString(const QDate &date, QLocale::FormatType type)
+QVariant QSystemLocalePrivate::toString(QDate date, QLocale::FormatType type)
 {
     SYSTEMTIME st;
     memset(&st, 0, sizeof(SYSTEMTIME));
@@ -413,7 +413,7 @@ QVariant QSystemLocalePrivate::toString(const QDate &date, QLocale::FormatType t
     return QString();
 }
 
-QVariant QSystemLocalePrivate::toString(const QTime &time, QLocale::FormatType type)
+QVariant QSystemLocalePrivate::toString(QTime time, QLocale::FormatType type)
 {
     SYSTEMTIME st;
     memset(&st, 0, sizeof(SYSTEMTIME));
diff --git a/src/corelib/time/qcalendar.cpp b/src/corelib/time/qcalendar.cpp
index f6bb242788..b569a6834c 100644
--- a/src/corelib/time/qcalendar.cpp
+++ b/src/corelib/time/qcalendar.cpp
@@ -810,7 +810,7 @@ bool QCalendar::isLuniSolar() const
 /*!
   Returns \c true if this calendar is solar.
 
-  A solar calendar is based primaril on the Sun's varying position in the sky,
+  A solar calendar is based primarily on the Sun's varying position in the sky,
   relative to the fixed stars.
 */
 bool QCalendar::isSolar() const
diff --git a/src/corelib/time/qdatetime.cpp b/src/corelib/time/qdatetime.cpp
index 020eac6dec..a9fc47e053 100644
--- a/src/corelib/time/qdatetime.cpp
+++ b/src/corelib/time/qdatetime.cpp
@@ -74,6 +74,7 @@
 #endif
 
 #include "qcalendar.h"
+#include "qgregoriancalendar_p.h"
 
 QT_BEGIN_NAMESPACE
 
@@ -105,6 +106,17 @@ static inline QDate fixedDate(QCalendar::YearMonthDay &&parts, QCalendar cal)
     return cal.dateFromParts(parts);
 }
 
+static inline QDate fixedDate(QCalendar::YearMonthDay &&parts)
+{
+    if (parts.year) {
+        parts.day = qMin(parts.day, QGregorianCalendar::monthLength(parts.month, parts.year));
+        qint64 jd;
+        if (QGregorianCalendar::julianFromParts(parts.year, parts.month, parts.day, &jd))
+            return QDate::fromJulianDay(jd);
+    }
+    return QDate();
+}
+
 /*****************************************************************************
   Date/Time formatting helper functions
  *****************************************************************************/
@@ -340,7 +352,8 @@ static int fromOffsetString(const QStringRef &offsetString, bool *valid) noexcep
 
 QDate::QDate(int y, int m, int d)
 {
-    *this = QCalendar().dateFromParts(y, m, d);
+    if (!QGregorianCalendar::julianFromParts(y, m, d, &jd))
+        jd = nullJd();
 }
 
 QDate::QDate(int y, int m, int d, QCalendar cal)
@@ -405,7 +418,12 @@ int QDate::year(QCalendar cal) const
 
 int QDate::year() const
 {
-    return year(QCalendar());
+    if (isValid()) {
+        const auto parts = QGregorianCalendar::partsFromJulian(jd);
+        if (parts.isValid())
+            return parts.year;
+    }
+    return 0;
 }
 
 /*!
@@ -452,7 +470,12 @@ int QDate::month(QCalendar cal) const
 
 int QDate::month() const
 {
-    return month(QCalendar());
+    if (isValid()) {
+        const auto parts = QGregorianCalendar::partsFromJulian(jd);
+        if (parts.isValid())
+            return parts.month;
+    }
+    return 0;
 }
 
 /*!
@@ -480,7 +503,12 @@ int QDate::day(QCalendar cal) const
 
 int QDate::day() const
 {
-    return day(QCalendar());
+    if (isValid()) {
+        const auto parts = QGregorianCalendar::partsFromJulian(jd);
+        if (parts.isValid())
+            return parts.day;
+    }
+    return 0;
 }
 
 /*!
@@ -507,7 +535,7 @@ int QDate::dayOfWeek(QCalendar cal) const
 
 int QDate::dayOfWeek() const
 {
-    return dayOfWeek(QCalendar());
+    return isValid() ? QGregorianCalendar::weekDayOfJulian(jd) : 0;
 }
 
 /*!
@@ -535,7 +563,12 @@ int QDate::dayOfYear(QCalendar cal) const
 
 int QDate::dayOfYear() const
 {
-    return dayOfYear(QCalendar());
+    if (isValid()) {
+        qint64 first;
+        if (QGregorianCalendar::julianFromParts(year(), 1, 1, &first))
+            return jd - first + 1;
+    }
+    return 0;
 }
 
 /*!
@@ -563,7 +596,12 @@ int QDate::daysInMonth(QCalendar cal) const
 
 int QDate::daysInMonth() const
 {
-    return daysInMonth(QCalendar());
+    if (isValid()) {
+        const auto parts = QGregorianCalendar::partsFromJulian(jd);
+        if (parts.isValid())
+            return QGregorianCalendar::monthLength(parts.month, parts.year);
+    }
+    return 0;
 }
 
 /*!
@@ -589,7 +627,7 @@ int QDate::daysInYear(QCalendar cal) const
 
 int QDate::daysInYear() const
 {
-    return daysInYear(QCalendar());
+    return isValid() ? QGregorianCalendar::leapTest(year()) ? 366 : 365 : 0;
 }
 
 /*!
@@ -1303,7 +1341,11 @@ QString QDate::toString(const QString &format, QCalendar cal) const
 */
 bool QDate::setDate(int year, int month, int day)
 {
-    return setDate(year, month, day, QCalendar());
+    if (QGregorianCalendar::julianFromParts(year, month, day, &jd))
+        return true;
+
+    jd = nullJd();
+    return false;
 }
 
 /*!
@@ -1339,7 +1381,7 @@ void QDate::getDate(int *year, int *month, int *day) const
 {
     QCalendar::YearMonthDay parts; // invalid by default
     if (isValid())
-        parts = QCalendar().partsFromDate(*this);
+        parts = QGregorianCalendar::partsFromJulian(jd);
 
     const bool ok = parts.isValid();
     if (year)
@@ -1428,7 +1470,30 @@ QDate QDate::addMonths(int nmonths, QCalendar cal) const
 
 QDate QDate::addMonths(int nmonths) const
 {
-    return addMonths(nmonths, QCalendar());
+    if (isNull())
+        return QDate();
+
+    if (nmonths == 0)
+        return *this;
+
+    auto parts = QGregorianCalendar::partsFromJulian(jd);
+
+    if (!parts.isValid())
+        return QDate();
+    Q_ASSERT(parts.year);
+
+    parts.month += nmonths;
+    while (parts.month <= 0) {
+        if (--parts.year) // skip over year 0
+            parts.month += 12;
+    }
+    while (parts.month > 12) {
+        parts.month -= 12;
+        if (!++parts.year) // skip over year 0
+            ++parts.year;
+    }
+
+    return fixedDate(std::move(parts));
 }
 
 /*!
@@ -1470,7 +1535,21 @@ QDate QDate::addYears(int nyears, QCalendar cal) const
 
 QDate QDate::addYears(int nyears) const
 {
-    return addYears(nyears, QCalendar());
+    if (isNull())
+        return QDate();
+
+    auto parts = QGregorianCalendar::partsFromJulian(jd);
+    if (!parts.isValid())
+        return QDate();
+
+    int old_y = parts.year;
+    parts.year += nyears;
+
+    // If we just crossed (or hit) a missing year zero, adjust year by +/- 1:
+    if ((old_y > 0) != (parts.year > 0) || !parts.year)
+        parts.year += nyears > 0 ? +1 : -1;
+
+    return fixedDate(std::move(parts));
 }
 
 /*!
@@ -1719,7 +1798,7 @@ QDate QDate::fromString(const QString &string, const QString &format)
 
 bool QDate::isValid(int year, int month, int day)
 {
-    return QCalendar().isDateValid(year, month, day);
+    return QGregorianCalendar::validParts(year, month, day);
 }
 
 /*!
@@ -1733,7 +1812,7 @@ bool QDate::isValid(int year, int month, int day)
 
 bool QDate::isLeapYear(int y)
 {
-    return QCalendar().isLeapYear(y);
+    return QGregorianCalendar::leapTest(y);
 }
 
 /*! \fn static QDate QDate::fromJulianDay(qint64 jd)
diff --git a/src/corelib/time/qdatetime.h b/src/corelib/time/qdatetime.h
index e1909b85e3..3eae8ebf64 100644
--- a/src/corelib/time/qdatetime.h
+++ b/src/corelib/time/qdatetime.h
@@ -58,7 +58,7 @@ class QCalendar;
 class QTimeZone;
 class QDateTime;
 
-class Q_CORE_EXPORT QDate
+class Q_CORE_EXPORT QDate // ### Qt 6: change to be used by value, not const &
 {
 public:
     enum MonthNameType { // ### Qt 6: remove, along with methods using it
@@ -138,7 +138,7 @@ public:
     Q_REQUIRED_RESULT QDate addYears(int years) const;
     Q_REQUIRED_RESULT QDate addMonths(int months, QCalendar cal) const;
     Q_REQUIRED_RESULT QDate addYears(int years, QCalendar cal) const;
-    qint64 daysTo(const QDate &) const;
+    qint64 daysTo(const QDate &) const; // ### Qt 6: QDate
 
     Q_DECL_CONSTEXPR bool operator==(const QDate &other) const { return jd == other.jd; }
     Q_DECL_CONSTEXPR bool operator!=(const QDate &other) const { return jd != other.jd; }
@@ -177,7 +177,7 @@ private:
 };
 Q_DECLARE_TYPEINFO(QDate, Q_MOVABLE_TYPE);
 
-class Q_CORE_EXPORT QTime
+class Q_CORE_EXPORT QTime // ### Qt 6: change to be used by value, not const &
 {
     explicit Q_DECL_CONSTEXPR QTime(int ms) : mds(ms)
     {}
@@ -203,9 +203,9 @@ public:
     bool setHMS(int h, int m, int s, int ms = 0);
 
     Q_REQUIRED_RESULT QTime addSecs(int secs) const;
-    int secsTo(const QTime &) const;
+    int secsTo(const QTime &) const; // ### Qt 6: plain QTime
     Q_REQUIRED_RESULT QTime addMSecs(int ms) const;
-    int msecsTo(const QTime &) const;
+    int msecsTo(const QTime &) const; // ### Qt 6: plain QTime
 
     Q_DECL_CONSTEXPR bool operator==(const QTime &other) const { return mds == other.mds; }
     Q_DECL_CONSTEXPR bool operator!=(const QTime &other) const { return mds != other.mds; }
@@ -236,7 +236,7 @@ private:
 
     friend class QDateTime;
     friend class QDateTimePrivate;
-#ifndef QT_NO_DATASTREAM
+#ifndef QT_NO_DATASTREAM // ### Qt 6: plain QTime
     friend Q_CORE_EXPORT QDataStream &operator<<(QDataStream &, const QTime &);
     friend Q_CORE_EXPORT QDataStream &operator>>(QDataStream &, QTime &);
 #endif
@@ -287,7 +287,7 @@ class Q_CORE_EXPORT QDateTime
 
 public:
     QDateTime() noexcept(Data::CanBeSmall);
-    explicit QDateTime(const QDate &);
+    explicit QDateTime(const QDate &); // ### Qt 6: plain QDate, QTime
     QDateTime(const QDate &, const QTime &, Qt::TimeSpec spec = Qt::LocalTime);
     // ### Qt 6: Merge with above with default offsetSeconds = 0
     QDateTime(const QDate &date, const QTime &time, Qt::TimeSpec spec, int offsetSeconds);
@@ -319,7 +319,7 @@ public:
     qint64 toMSecsSinceEpoch() const;
     qint64 toSecsSinceEpoch() const;
 
-    void setDate(const QDate &date);
+    void setDate(const QDate &date); // ### Qt 6: plain QDate
     void setTime(const QTime &time);
     void setTimeSpec(Qt::TimeSpec spec);
     void setOffsetFromUtc(int offsetSeconds);
diff --git a/src/corelib/time/qdatetimeparser.cpp b/src/corelib/time/qdatetimeparser.cpp
index 3c54a259a4..d0f34358b9 100644
--- a/src/corelib/time/qdatetimeparser.cpp
+++ b/src/corelib/time/qdatetimeparser.cpp
@@ -60,6 +60,9 @@
 
 QT_BEGIN_NAMESPACE
 
+template <typename T>
+using ShortVector = QVarLengthArray<T, 13>; // enough for month (incl. leap) and day-of-week names
+
 QDateTimeParser::~QDateTimeParser()
 {
 }
@@ -1538,7 +1541,7 @@ QDateTimeParser::parse(QString input, int position, const QDateTime &defaultValu
   length of overlap in *used (if \a used is non-NULL) and the first entry that
   overlapped this much in *usedText (if \a usedText is non-NULL).
  */
-static int findTextEntry(const QString &text, const QVector<QString> &entries, QString *usedText, int *used)
+static int findTextEntry(const QString &text, const ShortVector<QString> &entries, QString *usedText, int *used)
 {
     if (text.isEmpty())
         return -1;
@@ -1586,7 +1589,7 @@ int QDateTimeParser::findMonth(const QString &str1, int startMonth, int sectionI
 
     QLocale::FormatType type = sn.count == 3 ? QLocale::ShortFormat : QLocale::LongFormat;
     QLocale l = locale();
-    QVector<QString> monthNames;
+    ShortVector<QString> monthNames;
     monthNames.reserve(13 - startMonth);
     for (int month = startMonth; month <= 12; ++month)
         monthNames.append(calendar.monthName(l, month, year, type));
@@ -1605,7 +1608,7 @@ int QDateTimeParser::findDay(const QString &str1, int startDay, int sectionIndex
 
     QLocale::FormatType type = sn.count == 4 ? QLocale::LongFormat : QLocale::ShortFormat;
     QLocale l = locale();
-    QVector<QString> daysOfWeek;
+    ShortVector<QString> daysOfWeek;
     daysOfWeek.reserve(8 - startDay);
     for (int day = startDay; day <= 7; ++day)
         daysOfWeek.append(l.dayName(day, type));
diff --git a/src/corelib/time/qgregoriancalendar.cpp b/src/corelib/time/qgregoriancalendar.cpp
index d3db572aa7..447185d124 100644
--- a/src/corelib/time/qgregoriancalendar.cpp
+++ b/src/corelib/time/qgregoriancalendar.cpp
@@ -78,6 +78,11 @@ QCalendar::System QGregorianCalendar::calendarSystem() const
 
 bool QGregorianCalendar::isLeapYear(int year) const
 {
+    return leapTest(year);
+}
+
+bool QGregorianCalendar::leapTest(int year)
+{
     if (year == QCalendar::Unspecified)
         return false;
 
@@ -88,10 +93,37 @@ bool QGregorianCalendar::isLeapYear(int year) const
     return year % 4 == 0 && (year % 100 != 0 || year % 400 == 0);
 }
 
+// Duplicating code from QRomanCalendar, but inlining isLeapYear() as leapTest():
+int QGregorianCalendar::monthLength(int month, int year)
+{
+    if (month < 1 || month > 12)
+        return 0;
+
+    if (month == 2)
+        return leapTest(year) ? 29 : 28;
+
+    return 30 | ((month & 1) ^ (month >> 3));
+}
+
+bool QGregorianCalendar::validParts(int year, int month, int day)
+{
+    return year && 0 < day && day <= monthLength(month, year);
+}
+
+int QGregorianCalendar::weekDayOfJulian(qint64 jd)
+{
+    return qMod(jd, 7) + 1;
+}
+
 bool QGregorianCalendar::dateToJulianDay(int year, int month, int day, qint64 *jd) const
 {
+    return julianFromParts(year, month, day, jd);
+}
+
+bool QGregorianCalendar::julianFromParts(int year, int month, int day, qint64 *jd)
+{
     Q_ASSERT(jd);
-    if (!isDateValid(year, month, day))
+    if (!validParts(year, month, day))
         return false;
 
     if (year < 0)
@@ -112,6 +144,11 @@ bool QGregorianCalendar::dateToJulianDay(int year, int month, int day, qint64 *j
 
 QCalendar::YearMonthDay QGregorianCalendar::julianDayToDate(qint64 jd) const
 {
+    return partsFromJulian(jd);
+}
+
+QCalendar::YearMonthDay QGregorianCalendar::partsFromJulian(qint64 jd)
+{
     /*
      * Math from The Calendar FAQ at http://www.tondering.dk/claus/cal/julperiod.php
      * This formula is correct for all julian days, when using mathematical integer
diff --git a/src/corelib/time/qgregoriancalendar_p.h b/src/corelib/time/qgregoriancalendar_p.h
index 4e6c42ef76..191f9c127b 100644
--- a/src/corelib/time/qgregoriancalendar_p.h
+++ b/src/corelib/time/qgregoriancalendar_p.h
@@ -75,6 +75,14 @@ public:
                       QLocale::FormatType format) const override;
     QString standaloneMonthName(const QLocale &locale, int month, int year,
                                 QLocale::FormatType format) const override;
+
+    // Static optimized versions for the benefit of QDate:
+    static int weekDayOfJulian(qint64 jd);
+    static bool leapTest(int year);
+    static int monthLength(int month, int year);
+    static bool validParts(int year, int month, int day);
+    static QCalendar::YearMonthDay partsFromJulian(qint64 jd);
+    static bool julianFromParts(int year, int month, int day, qint64 *jd);
 };
 
 QT_END_NAMESPACE