use XCalendar4 local date/time in CalendarWrapper, tdf#63230

Replaces the three-step timezone+DST correction. Hopefully ICU does take these
into account, but this needs to be double-rechecked and if necessary
correction be implemented at XCalendar4::setLocalDateTime()

See also
http://userguide.icu-project.org/datetime/calendar#TOC-Ambiguous-Wall-Clock-Time-Resolution
Interpreting as standard time for non-existing times sounds like what we need
and covers the dreaded "00:00-01:00 doesn't exist" case that decremented the
day and was fixed here with the now removed workaround.

1 files changed, 2 insertions, 41 deletions

diff --git a/unotools/source/i18n/calendarwrapper.cxx b/unotools/source/i18n/calendarwrapper.cxx
index 6d082f2fc447..27c1b478f2f7 100644
--- a/unotools/source/i18n/calendarwrapper.cxx
+++ b/unotools/source/i18n/calendarwrapper.cxx
@@ -165,42 +165,7 @@ void CalendarWrapper::setLocalDateTime( double fTimeInDays )
     {
         if ( xC.is() )
         {
-            // First set a nearby value to obtain the timezone and DST offset.
-            // This is necessary to let ICU choose the corresponding
-            // OlsonTimeZone transitions. Since ICU incorporates also
-            // historical data even the timezone may differ for different
-            // dates! (Which was the cause for #i76623# when the timezone of a
-            // previously set date was used.) Timezone may also include
-            // seconds, so use milliseconds field as well.
-            xC->setDateTime( fTimeInDays );
-            sal_Int32 nZone1 = getZoneOffsetInMillis();
-            sal_Int32 nDST1  = getDSTOffsetInMillis();
-            double fLoc = fTimeInDays - (double)(nZone1 + nDST1) / MILLISECONDS_PER_DAY;
-            xC->setDateTime( fLoc );
-            sal_Int32 nZone2 = getZoneOffsetInMillis();
-            sal_Int32 nDST2  = getDSTOffsetInMillis();
-            // If DSTs differ after calculation, we crossed boundaries. Do it
-            // again, this time using the DST corrected initial value for the
-            // real local time.
-            // See also localtime/gmtime conversion pitfalls at
-            // http://www.erack.de/download/timetest.c
-            if ( nDST1 != nDST2 )
-            {
-                fLoc = fTimeInDays - (double)(nZone2 + nDST2) / MILLISECONDS_PER_DAY;
-                xC->setDateTime( fLoc );
-                // #i17222# If the DST onset rule says to switch from 00:00 to
-                // 01:00 and we tried to set onsetDay 00:00 with DST, the
-                // result was onsetDay-1 23:00 and no DST, which is not what we
-                // want. So once again without DST, resulting in onsetDay
-                // 01:00 and DST. Yes, this seems to be weird, but logically
-                // correct.
-                sal_Int32 nDST3 = getDSTOffsetInMillis();
-                if ( nDST2 != nDST3 && !nDST3 )
-                {
-                    fLoc = fTimeInDays - (double)(nZone2 + nDST3) / MILLISECONDS_PER_DAY;
-                    xC->setDateTime( fLoc );
-                }
-            }
+            xC->setLocalDateTime( fTimeInDays );
         }
     }
     catch (const Exception& e)
@@ -215,11 +180,7 @@ double CalendarWrapper::getLocalDateTime() const
     {
         if ( xC.is() )
         {
-            double fTimeInDays = xC->getDateTime();
-            sal_Int32 nZone = getZoneOffsetInMillis();
-            sal_Int32 nDST = getDSTOffsetInMillis();
-            fTimeInDays += (double)(nZone + nDST) / MILLISECONDS_PER_DAY;
-            return fTimeInDays;
+            return xC->getLocalDateTime();
         }
     }
     catch (const Exception& e)