Fix bug about daylight saving missing on Symbian platfrom.

Daylight saving support for QDateTime is missing from Symbian
platform. This is bug fix for QTBUG-6859. This bug was fixed by
commit 2a20705. However, this original fix was removed by 01cf310d2
because of different implementation before S60 5.0 platform. This
fix is re-applied since Qt is not going to support S60 3.x platform.

Task-number: QTBUG-6859
Reviewed-by: Trust Me

4 files changed, 46 insertions, 26 deletions

diff --git a/src/corelib/corelib.pro b/src/corelib/corelib.pro
index 58d2c7b..9673861 100644
--- a/src/corelib/corelib.pro
+++ b/src/corelib/corelib.pro
@@ -45,4 +45,5 @@ symbian: {
                   "UNPAGED" \
                   "$${LITERAL_HASH}endif"
     MMP_RULES += pagingBlock
+    LIBS += -ltzclient
 }
diff --git a/src/corelib/tools/qdatetime.cpp b/src/corelib/tools/qdatetime.cpp
index 4303731..a6fee43 100644
--- a/src/corelib/tools/qdatetime.cpp
+++ b/src/corelib/tools/qdatetime.cpp
@@ -75,6 +75,7 @@
 
 #if defined(Q_OS_SYMBIAN)
 #include <e32std.h>
+#include <tz.h>
 #endif
 
 QT_BEGIN_NAMESPACE
@@ -4029,23 +4030,32 @@ static QDateTimePrivate::Spec utcToLocal(QDate &date, QTime &time)
 #elif defined(Q_OS_SYMBIAN)
     // months and days are zero index based
     _LIT(KUnixEpoch, "19700000:000000.000000");
-    TTimeIntervalSeconds utcOffset = User::UTCOffset();
     TTimeIntervalSeconds tTimeIntervalSecsSince1Jan1970UTC(secsSince1Jan1970UTC);
     TTime epochTTime;
     TInt err = epochTTime.Set(KUnixEpoch);
     tm res;
     if(err == KErrNone) {
         TTime utcTTime = epochTTime + tTimeIntervalSecsSince1Jan1970UTC;
-        utcTTime = utcTTime + utcOffset;
-        TDateTime utcDateTime = utcTTime.DateTime();
-        res.tm_sec = utcDateTime.Second();
-        res.tm_min = utcDateTime.Minute();
-        res.tm_hour = utcDateTime.Hour();
-        res.tm_mday = utcDateTime.Day() + 1; // non-zero based index for tm struct
-        res.tm_mon = utcDateTime.Month();
-        res.tm_year = utcDateTime.Year() - 1900;
-        res.tm_isdst = 0;
-        brokenDown = &res;
+        TRAP(err,
+            RTz tz;
+            User::LeaveIfError(tz.Connect());
+            CleanupClosePushL(tz);
+            res.tm_isdst = tz.IsDaylightSavingOnL(*tz.GetTimeZoneIdL(),utcTTime);
+            User::LeaveIfError(tz.ConvertToLocalTime(utcTTime));
+            CleanupStack::PopAndDestroy(&tz));
+        if (KErrNone == err) {
+            TDateTime localDateTime = utcTTime.DateTime();
+            res.tm_sec = localDateTime.Second();
+            res.tm_min = localDateTime.Minute();
+            res.tm_hour = localDateTime.Hour();
+            res.tm_mday = localDateTime.Day() + 1; // non-zero based index for tm struct
+            res.tm_mon = localDateTime.Month();
+            res.tm_year = localDateTime.Year() - 1900;
+            // Symbian's timezone server doesn't know how to handle DST before year 1997
+            if (res.tm_year < 97)
+                res.tm_isdst = -1;
+            brokenDown = &res;
+        }
     }
 #elif !defined(QT_NO_THREAD) && defined(_POSIX_THREAD_SAFE_FUNCTIONS)
     // use the reentrant version of localtime() where available
@@ -4120,23 +4130,27 @@ static void localToUtc(QDate &date, QTime &time, int isdst)
 #elif defined(Q_OS_SYMBIAN)
     // months and days are zero index based
     _LIT(KUnixEpoch, "19700000:000000.000000");
-    TTimeIntervalSeconds utcOffset = TTimeIntervalSeconds(0 - User::UTCOffset().Int());
     TTimeIntervalSeconds tTimeIntervalSecsSince1Jan1970UTC(secsSince1Jan1970UTC);
     TTime epochTTime;
     TInt err = epochTTime.Set(KUnixEpoch);
     tm res;
     if(err == KErrNone) {
-        TTime utcTTime = epochTTime + tTimeIntervalSecsSince1Jan1970UTC;
-        utcTTime = utcTTime + utcOffset;
-        TDateTime utcDateTime = utcTTime.DateTime();
-        res.tm_sec = utcDateTime.Second();
-        res.tm_min = utcDateTime.Minute();
-        res.tm_hour = utcDateTime.Hour();
-        res.tm_mday = utcDateTime.Day() + 1; // non-zero based index for tm struct
-        res.tm_mon = utcDateTime.Month();
-        res.tm_year = utcDateTime.Year() - 1900;
-        res.tm_isdst = (int)isdst;
-        brokenDown = &res;
+        TTime localTTime = epochTTime + tTimeIntervalSecsSince1Jan1970UTC;
+        RTz tz;
+        if (KErrNone == tz.Connect()) {
+            if (KErrNone == tz.ConvertToUniversalTime(localTTime)) {
+                TDateTime utcDateTime = localTTime.DateTime();
+                res.tm_sec = utcDateTime.Second();
+                res.tm_min = utcDateTime.Minute();
+                res.tm_hour = utcDateTime.Hour();
+                res.tm_mday = utcDateTime.Day() + 1; // non-zero based index for tm struct
+                res.tm_mon = utcDateTime.Month();
+                res.tm_year = utcDateTime.Year() - 1900;
+                res.tm_isdst = (int)isdst;
+                brokenDown = &res;
+            }
+        tz.Close();
+        }
     }
 #elif !defined(QT_NO_THREAD) && defined(_POSIX_THREAD_SAFE_FUNCTIONS)
     // use the reentrant version of gmtime() where available
diff --git a/tests/auto/qdatetime/qdatetime.pro b/tests/auto/qdatetime/qdatetime.pro
index 08a321e..a3f3091 100644
--- a/tests/auto/qdatetime/qdatetime.pro
+++ b/tests/auto/qdatetime/qdatetime.pro
@@ -1,5 +1,4 @@
 load(qttest_p4)
-
 SOURCES += tst_qdatetime.cpp
 QT = core
 
@@ -10,6 +9,5 @@ win32-msvc|win32-msvc9x {
     QMAKE_CFLAGS_RELEASE -= -O1
     QMAKE_CXXFLAGS_RELEASE -= -O1
 }
-
-
 CONFIG += parallel_test
+HEADERS = tst_qdatetime.loc
diff --git a/tests/auto/qdatetime/tst_qdatetime.cpp b/tests/auto/qdatetime/tst_qdatetime.cpp
index 95995e8..5462250 100644
--- a/tests/auto/qdatetime/tst_qdatetime.cpp
+++ b/tests/auto/qdatetime/tst_qdatetime.cpp
@@ -155,9 +155,16 @@ Q_DECLARE_METATYPE(QTime)
 
 tst_QDateTime::tst_QDateTime()
 {
+#ifdef Q_OS_SYMBIAN
+    // Symbian's timezone server cannot handle DST correctly for dates before year 1997
+    uint x1 = QDateTime(QDate(2000, 1, 1), QTime()).toTime_t();
+    uint x2 = QDateTime(QDate(2000, 6, 1), QTime()).toTime_t();
+    europeanTimeZone = (x1 == 946681200 && x2 == 959810400);
+#else
     uint x1 = QDateTime(QDate(1990, 1, 1), QTime()).toTime_t();
     uint x2 = QDateTime(QDate(1990, 6, 1), QTime()).toTime_t();
     europeanTimeZone = (x1 == 631148400 && x2 == 644191200);
+#endif
 }
 
 tst_QDateTime::~tst_QDateTime()