8229471: Calendar under a specific timezone changes HOUR field when MILLISECOND field is changed

[Yano, Masanori]

Hi Naoto,

Thank you for replying. I understand that this behavior is expected.
I will consider the existing behavior.

Regards,
Masanori Yano

> -----Original Message-----
> From: naoto.sato at oracle.com [mailto:naoto.sato at oracle.com]
> Sent: Friday, September 13, 2019 5:25 AM
> To: Yano, Masanori <yano-masanori at jp.fujitsu.com>;
> 'core-libs-dev at openjdk.java.net' <core-libs-dev at openjdk.java.net>
> Cc: i18n-dev at openjdk.java.net
> Subject: Re: 8229471: Calendar under a specific timezone changes HOUR field
> when MILLISECOND field is changed
> 
> Hi Masanori,
> 
> Thank you for looking at the issue and your contribution. I am also
> investigating it (as an assignee of the bug), and looking at this old
> issue:
> 
> https://bugs.openjdk.java.net/browse/JDK-4177484
> 
> The comment suggests that the existing behavior is the expected one. In
> fact, your fix would break some regression test cases in
> jdk/java/util/Calendar/CalendarRegression.java.
> 
> I will need some more archaeological investigation, but I am inclined to
> close it as not an issue at the moment.
> 
> Naoto
> 
> On 9/12/19 12:16 AM, Yano, Masanori wrote:
> > Hello.
> >
> > I think JDK-8229471 occurs because a change of TimeZone is not considered
> in getTime().
> > To resolve this problem, isTimeSet flag must be set to false when
> setTimeZone() is called.
> >
> > Please review the following change.
> >
> > diff -r e1269de19aa5
> src/java.base/share/classes/java/util/Calendar.java
> > --- a/src/java.base/share/classes/java/util/Calendar.java      Thu Aug
> 22 14:09:36 2019 -0700
> > +++ b/src/java.base/share/classes/java/util/Calendar.java      Thu Sep
> 12 11:45:37 2019 +0900
> > @@ -2901,7 +2901,7 @@
> >            * generally, a call to setTimeZone() affects calls to set()
> BEFORE AND
> >            * AFTER it up to the next call to complete().
> >            */
> > -        areAllFieldsSet = areFieldsSet = false;
> > +        isTimeSet = areAllFieldsSet = areFieldsSet = false;
> >       }
> >
> >       /**
> > diff -r e1269de19aa5 test/jdk/java/util/Calendar/Bug8229471.java
> > --- /dev/null  Thu Jan 01 00:00:00 1970 +0000
> > +++ b/test/jdk/java/util/Calendar/Bug8229471.java      Thu Sep 12
> 11:45:37 2019 +0900
> > @@ -0,0 +1,22 @@
> > +/*
> > + *@test
> > + *@bug 8229471
> > + *@summary test for recompute when Calendar.setTimeZone()  */
> > +
> > +import java.util.Calendar;
> > +import java.util.Date;
> > +import java.util.Locale;
> > +import java.util.TimeZone;
> > +
> > +public class Bug8229471 {
> > +    public static void main(String[] args) throws Exception {
> > +        Calendar calendar = Calendar.getInstance(new Locale("en",
> "US"));
> > +        Date date1 = calendar.getTime();
> > +
> calendar.setTimeZone(TimeZone.getTimeZone("Europe/Budapest"));
> > +        Date date2 = calendar.getTime();
> > +        if (date1.equals(date2)) {
> > +            throw new RuntimeException("Bug8229471: failed. TimeZone
> is not applied.");
> > +        }
> > +    }
> > +}
> >
> > Regards,
> > Masanori Yano
> >