Fix conversion between JavaScript Date and QDateTime

Use JavaScriptCore's conversion functions rather than our own
(incomplete) implementation.
Specifically, this means daylight saving time is finally
handled correctly on Windows.

Task-number: QTBUG-9770
Reviewed-by: Olivier Goffart

6 files changed, 53 insertions, 427 deletions

diff --git a/src/script/api/qscriptengine.cpp b/src/script/api/qscriptengine.cpp
index 655026c..7bccffe 100644
--- a/src/script/api/qscriptengine.cpp
+++ b/src/script/api/qscriptengine.cpp
@@ -438,6 +438,53 @@ qsreal ToNumber(const QString &value)
 
 #endif
 
+static const qsreal MsPerSecond = 1000.0;
+
+static inline int MsFromTime(qsreal t)
+{
+    int r = int(::fmod(t, MsPerSecond));
+    return (r >= 0) ? r : r + int(MsPerSecond);
+}
+
+/*!
+  \internal
+  Converts a JS date value (milliseconds) to a QDateTime (local time).
+*/
+QDateTime MsToDateTime(JSC::ExecState *exec, qsreal t)
+{
+    if (qIsNaN(t))
+        return QDateTime();
+    JSC::GregorianDateTime tm;
+    JSC::msToGregorianDateTime(exec, t, /*output UTC=*/true, tm);
+    int ms = MsFromTime(t);
+    QDateTime convertedUTC = QDateTime(QDate(tm.year + 1900, tm.month + 1, tm.monthDay),
+                                       QTime(tm.hour, tm.minute, tm.second, ms), Qt::UTC);
+    return convertedUTC.toLocalTime();
+}
+
+/*!
+  \internal
+  Converts a QDateTime to a JS date value (milliseconds).
+*/
+qsreal DateTimeToMs(JSC::ExecState *exec, const QDateTime &dt)
+{
+    if (!dt.isValid())
+        return qSNaN();
+    QDateTime utc = dt.toUTC();
+    QDate date = utc.date();
+    QTime time = utc.time();
+    JSC::GregorianDateTime tm;
+    tm.year = date.year() - 1900;
+    tm.month = date.month() - 1;
+    tm.monthDay = date.day();
+    tm.weekDay = date.dayOfWeek();
+    tm.yearDay = date.dayOfYear();
+    tm.hour = time.hour();
+    tm.minute = time.minute();
+    tm.second = time.second();
+    return JSC::gregorianDateTimeToMS(exec, tm, time.msec(), /*inputIsUTC=*/true);
+}
+
 void GlobalClientData::mark(JSC::MarkStack& markStack)
 {
     engine->mark(markStack);
diff --git a/src/script/api/qscriptengine_p.h b/src/script/api/qscriptengine_p.h
index 1b35704..c71465d 100644
--- a/src/script/api/qscriptengine_p.h
+++ b/src/script/api/qscriptengine_p.h
@@ -50,7 +50,6 @@
 #include "bridge/qscriptobject_p.h"
 #include "bridge/qscriptqobject_p.h"
 #include "bridge/qscriptvariant_p.h"
-#include "utils/qscriptdate_p.h"
 
 #include "DateConstructor.h"
 #include "DateInstance.h"
@@ -119,6 +118,9 @@ namespace QScript
     inline QString ToString(qsreal);
 #endif
 
+    QDateTime MsToDateTime(JSC::ExecState *, qsreal);
+    qsreal DateTimeToMs(JSC::ExecState *, const QDateTime &);
+
     //some conversion helper functions
     inline QScriptEnginePrivate *scriptEngineFromExec(const JSC::ExecState *exec);
     bool isFunction(JSC::JSValue value);
@@ -861,7 +863,7 @@ inline JSC::JSValue QScriptEnginePrivate::newDate(JSC::ExecState *exec, qsreal v
 
 inline JSC::JSValue QScriptEnginePrivate::newDate(JSC::ExecState *exec, const QDateTime &value)
 {
-    return newDate(exec, QScript::FromDateTime(value));
+    return newDate(exec, QScript::DateTimeToMs(exec, value));
 }
 
 inline JSC::JSValue QScriptEnginePrivate::newObject()
@@ -994,12 +996,12 @@ inline JSC::UString QScriptEnginePrivate::toString(JSC::ExecState *exec, JSC::JS
     return str;
 }
 
-inline QDateTime QScriptEnginePrivate::toDateTime(JSC::ExecState *, JSC::JSValue value)
+inline QDateTime QScriptEnginePrivate::toDateTime(JSC::ExecState *exec, JSC::JSValue value)
 {
     if (!isDate(value))
         return QDateTime();
     qsreal t = static_cast<JSC::DateInstance*>(JSC::asObject(value))->internalNumber();
-    return QScript::ToDateTime(t, Qt::LocalTime);
+    return QScript::MsToDateTime(exec, t);
 }
 
 inline QObject *QScriptEnginePrivate::toQObject(JSC::ExecState *exec, JSC::JSValue value)
diff --git a/src/script/script.pri b/src/script/script.pri
index 2ee1a82..9cd71d3 100644
--- a/src/script/script.pri
+++ b/src/script/script.pri
@@ -1,4 +1,3 @@
 include($$PWD/api/api.pri)
 include($$PWD/bridge/bridge.pri)
 include($$PWD/parser/parser.pri)
-include($$PWD/utils/utils.pri)
diff --git a/src/script/utils/qscriptdate.cpp b/src/script/utils/qscriptdate.cpp
deleted file mode 100644
index 5980256..0000000
--- a/src/script/utils/qscriptdate.cpp
+++ /dev/null
@@ -1,365 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
-** All rights reserved.
-** Contact: Nokia Corporation (qt-info@nokia.com)
-**
-** This file is part of the QtScript module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL-ONLY$
-** GNU Lesser General Public License Usage
-** This file may be used under the terms of the GNU Lesser
-** General Public License version 2.1 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL included in the
-** packaging of this file.  Please review the following information to
-** ensure the GNU Lesser General Public License version 2.1 requirements
-** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
-**
-** If you have questions regarding the use of this file, please contact
-** Nokia at qt-info@nokia.com.
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#include "qscriptdate_p.h"
-
-#include <QtCore/qnumeric.h>
-#include <QtCore/qstringlist.h>
-
-#include <math.h>
-
-#ifndef Q_WS_WIN
-#   include <time.h>
-#   include <sys/time.h>
-#else
-#   include <windows.h>
-#endif
-
-QT_BEGIN_NAMESPACE
-
-namespace QScript {
-
-qsreal ToInteger(qsreal n);
-
-static const qsreal HoursPerDay = 24.0;
-static const qsreal MinutesPerHour = 60.0;
-static const qsreal SecondsPerMinute = 60.0;
-static const qsreal msPerSecond = 1000.0;
-static const qsreal msPerMinute = 60000.0;
-static const qsreal msPerHour = 3600000.0;
-static const qsreal msPerDay = 86400000.0;
-
-static qsreal LocalTZA = 0.0; // initialized at startup
-
-static inline qsreal TimeWithinDay(qsreal t)
-{
-    qsreal r = ::fmod(t, msPerDay);
-    return (r >= 0) ? r : r + msPerDay;
-}
-
-static inline int HourFromTime(qsreal t)
-{
-    int r = int(::fmod(::floor(t / msPerHour), HoursPerDay));
-    return (r >= 0) ? r : r + int(HoursPerDay);
-}
-
-static inline int MinFromTime(qsreal t)
-{
-    int r = int(::fmod(::floor(t / msPerMinute), MinutesPerHour));
-    return (r >= 0) ? r : r + int(MinutesPerHour);
-}
-
-static inline int SecFromTime(qsreal t)
-{
-    int r = int(::fmod(::floor(t / msPerSecond), SecondsPerMinute));
-    return (r >= 0) ? r : r + int(SecondsPerMinute);
-}
-
-static inline int msFromTime(qsreal t)
-{
-    int r = int(::fmod(t, msPerSecond));
-    return (r >= 0) ? r : r + int(msPerSecond);
-}
-
-static inline qsreal Day(qsreal t)
-{
-    return ::floor(t / msPerDay);
-}
-
-static inline qsreal DaysInYear(qsreal y)
-{
-    if (::fmod(y, 4))
-        return 365;
-
-    else if (::fmod(y, 100))
-        return 366;
-
-    else if (::fmod(y, 400))
-        return 365;
-
-    return 366;
-}
-
-static inline qsreal DayFromYear(qsreal y)
-{
-    return 365 * (y - 1970)
-        + ::floor((y - 1969) / 4)
-        - ::floor((y - 1901) / 100)
-        + ::floor((y - 1601) / 400);
-}
-
-static inline qsreal TimeFromYear(qsreal y)
-{
-    return msPerDay * DayFromYear(y);
-}
-
-static inline qsreal YearFromTime(qsreal t)
-{
-    int y = 1970;
-    y += (int) ::floor(t / (msPerDay * 365.2425));
-
-    qsreal t2 = TimeFromYear(y);
-    return (t2 > t) ? y - 1 : ((t2 + msPerDay * DaysInYear(y)) <= t) ? y + 1 : y;
-}
-
-static inline bool InLeapYear(qsreal t)
-{
-    qsreal x = DaysInYear(YearFromTime(t));
-    if (x == 365)
-        return 0;
-
-    Q_ASSERT (x == 366);
-    return 1;
-}
-
-static inline qsreal DayWithinYear(qsreal t)
-{
-    return Day(t) - DayFromYear(YearFromTime(t));
-}
-
-static inline qsreal MonthFromTime(qsreal t)
-{
-    qsreal d = DayWithinYear(t);
-    qsreal l = InLeapYear(t);
-
-    if (d < 31.0)
-        return 0;
-
-    else if (d < 59.0 + l)
-        return 1;
-
-    else if (d < 90.0 + l)
-        return 2;
-
-    else if (d < 120.0 + l)
-        return 3;
-
-    else if (d < 151.0 + l)
-        return 4;
-
-    else if (d < 181.0 + l)
-        return 5;
-
-    else if (d < 212.0 + l)
-        return 6;
-
-    else if (d < 243.0 + l)
-        return 7;
-
-    else if (d < 273.0 + l)
-        return 8;
-
-    else if (d < 304.0 + l)
-        return 9;
-
-    else if (d < 334.0 + l)
-        return 10;
-
-    else if (d < 365.0 + l)
-        return 11;
-
-    return qSNaN(); // ### assert?
-}
-
-static inline qsreal DateFromTime(qsreal t)
-{
-    int m = (int) ToInteger(MonthFromTime(t));
-    qsreal d = DayWithinYear(t);
-    qsreal l = InLeapYear(t);
-
-    switch (m) {
-    case 0: return d + 1.0;
-    case 1: return d - 30.0;
-    case 2: return d - 58.0 - l;
-    case 3: return d - 89.0 - l;
-    case 4: return d - 119.0 - l;
-    case 5: return d - 150.0 - l;
-    case 6: return d - 180.0 - l;
-    case 7: return d - 211.0 - l;
-    case 8: return d - 242.0 - l;
-    case 9: return d - 272.0 - l;
-    case 10: return d - 303.0 - l;
-    case 11: return d - 333.0 - l;
-    }
-
-    return qSNaN(); // ### assert
-}
-
-static inline qsreal WeekDay(qsreal t)
-{
-    qsreal r = ::fmod (Day(t) + 4.0, 7.0);
-    return (r >= 0) ? r : r + 7.0;
-}
-
-
-static inline qsreal MakeTime(qsreal hour, qsreal min, qsreal sec, qsreal ms)
-{
-    return ((hour * MinutesPerHour + min) * SecondsPerMinute + sec) * msPerSecond + ms;
-}
-
-static inline qsreal DayFromMonth(qsreal month, qsreal leap)
-{
-    switch ((int) month) {
-    case 0: return 0;
-    case 1: return 31.0;
-    case 2: return 59.0 + leap;
-    case 3: return 90.0 + leap;
-    case 4: return 120.0 + leap;
-    case 5: return 151.0 + leap;
-    case 6: return 181.0 + leap;
-    case 7: return 212.0 + leap;
-    case 8: return 243.0 + leap;
-    case 9: return 273.0 + leap;
-    case 10: return 304.0 + leap;
-    case 11: return 334.0 + leap;
-    }
-
-    return qSNaN(); // ### assert?
-}
-
-static qsreal MakeDay(qsreal year, qsreal month, qsreal day)
-{
-    year += ::floor(month / 12.0);
-
-    month = ::fmod(month, 12.0);
-    if (month < 0)
-        month += 12.0;
-
-    qsreal t = TimeFromYear(year);
-    qsreal leap = InLeapYear(t);
-
-    day += ::floor(t / msPerDay);
-    day += DayFromMonth(month, leap);
-
-    return day - 1;
-}
-
-static inline qsreal MakeDate(qsreal day, qsreal time)
-{
-    return day * msPerDay + time;
-}
-
-static inline qsreal DaylightSavingTA(double t)
-{
-#ifndef Q_WS_WIN
-    long int tt = (long int)(t / msPerSecond);
-    struct tm *tmtm = localtime((const time_t*)&tt);
-    if (! tmtm)
-        return 0;
-    return (tmtm->tm_isdst > 0) ? msPerHour : 0;
-#else
-    Q_UNUSED(t);
-    /// ### implement me
-    return 0;
-#endif
-}
-
-static inline qsreal LocalTime(qsreal t)
-{
-    return t + LocalTZA + DaylightSavingTA(t);
-}
-
-static inline qsreal UTC(qsreal t)
-{
-    return t - LocalTZA - DaylightSavingTA(t - LocalTZA);
-}
-
-static inline qsreal TimeClip(qsreal t)
-{
-    if (! qIsFinite(t) || fabs(t) > 8.64e15)
-        return qSNaN();
-    return ToInteger(t);
-}
-
-static qsreal getLocalTZA()
-{
-#ifndef Q_WS_WIN
-    struct tm* t;
-    time_t curr;
-    time(&curr);
-    t = localtime(&curr);
-    time_t locl = mktime(t);
-    t = gmtime(&curr);
-    time_t globl = mktime(t);
-    return double(locl - globl) * 1000.0;
-#else
-    TIME_ZONE_INFORMATION tzInfo;
-    GetTimeZoneInformation(&tzInfo);
-    return -tzInfo.Bias * 60.0 * 1000.0;
-#endif
-}
-
-/*!
-  \internal
-
-  Converts the QDateTime \a dt to an ECMA Date value (in UTC form).
-*/
-qsreal FromDateTime(const QDateTime &dt)
-{
-    if (!dt.isValid())
-        return qSNaN();
-    if (!LocalTZA) // ### move
-        LocalTZA = getLocalTZA();
-    QDate date = dt.date();
-    QTime taim = dt.time();
-    int year = date.year();
-    int month = date.month() - 1;
-    int day = date.day();
-    int hours = taim.hour();
-    int mins = taim.minute();
-    int secs = taim.second();
-    int ms = taim.msec();
-    double t = MakeDate(MakeDay(year, month, day),
-                        MakeTime(hours, mins, secs, ms));
-    if (dt.timeSpec() == Qt::LocalTime)
-        t = UTC(t);
-    return TimeClip(t);
-}
-
-/*!
-  \internal
-
-  Converts the ECMA Date value \tt (in UTC form) to QDateTime
-  according to \a spec.
-*/
-QDateTime ToDateTime(qsreal t, Qt::TimeSpec spec)
-{
-    if (qIsNaN(t))
-        return QDateTime();
-    if (!LocalTZA) // ### move
-        LocalTZA = getLocalTZA();
-    if (spec == Qt::LocalTime)
-        t = LocalTime(t);
-    int year = int(YearFromTime(t));
-    int month = int(MonthFromTime(t) + 1);
-    int day = int(DateFromTime(t));
-    int hours = HourFromTime(t);
-    int mins = MinFromTime(t);
-    int secs = SecFromTime(t);
-    int ms = msFromTime(t);
-    return QDateTime(QDate(year, month, day), QTime(hours, mins, secs, ms), spec);
-}
-
-} // namespace QScript
-
-QT_END_NAMESPACE
diff --git a/src/script/utils/qscriptdate_p.h b/src/script/utils/qscriptdate_p.h
deleted file mode 100644
index b9c9fd4..0000000
--- a/src/script/utils/qscriptdate_p.h
+++ /dev/null
@@ -1,52 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
-** All rights reserved.
-** Contact: Nokia Corporation (qt-info@nokia.com)
-**
-** This file is part of the QtScript module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL-ONLY$
-** GNU Lesser General Public License Usage
-** This file may be used under the terms of the GNU Lesser
-** General Public License version 2.1 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL included in the
-** packaging of this file.  Please review the following information to
-** ensure the GNU Lesser General Public License version 2.1 requirements
-** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
-**
-** If you have questions regarding the use of this file, please contact
-** Nokia at qt-info@nokia.com.
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#ifndef QSCRIPTDATE_P_H
-#define QSCRIPTDATE_P_H
-
-//
-//  W A R N I N G
-//  -------------
-//
-// This file is not part of the Qt API.  It exists purely as an
-// implementation detail.  This header file may change from version to
-// version without notice, or even be removed.
-//
-// We mean it.
-//
-
-#include <QtCore/qdatetime.h>
-
-QT_BEGIN_NAMESPACE
-
-typedef double qsreal;
-
-namespace QScript
-{
-    qsreal FromDateTime(const QDateTime &dt);
-    QDateTime ToDateTime(qsreal t, Qt::TimeSpec spec);
-}
-
-QT_END_NAMESPACE
-
-#endif
diff --git a/src/script/utils/utils.pri b/src/script/utils/utils.pri
deleted file mode 100644
index d8302d5..0000000
--- a/src/script/utils/utils.pri
+++ /dev/null
@@ -1,5 +0,0 @@
-SOURCES += \
-    $$PWD/qscriptdate.cpp
-
-HEADERS += \
-    $$PWD/qscriptdate_p.h