Re: [xslt] Bug in EXSLT date:week-in-year()

["William M. Brack" <wbrack mmm com hk>]

Thomas Broyer said:
> Hi there,
>
> It's been a long time since I last worked on LibXML/LibXSLT/LibEXSLT,
> many people here might not know about meâ?¦ I am the man who drafted the
> extension framework and committed libexslt, something like 4 or 5 years agoâ?¦
>
> Today, I had to add week numbers to a DHTML "datepicker" (screenshot
> attached for curious ones) so I went on Gnome CVS to borrow my own
> "week-in-year" code. It actually happens it's buggy, and it seems nobody
> reported it.
>
> Sorry not to post into Bugzilla nor patch into CVS directly but I don't
> remember my password nor the email address I used at that timeâ?¦
>
> When computing the week number, it always consider the year to begin on
> Monday, while it should use the "day in week" of January 1st. The fix is
> simple; instead of the following lines:
>
>     fdiw = (_exsltDateDayInWeek(fdiy, dt->value.date.year) + 6) % 7;
>
>     ret = DAY_IN_YEAR(dt->value.date.day, dt->value.date.mon,
>                       dt->value.date.year) / 7;
>
> Put these ones:
>
>     fdiw = (_exsltDateDayInWeek(fdiy, dt->value.date.year) + 6) % 7;
>
>     ret = (DAY_IN_YEAR(dt->value.date.day, dt->value.date.mon,
>                       dt->value.date.year) + fdiw) / 7;
>
> The only change is to adjust the DAY_IN_YEAR result by the "January 1st
> day-in-week" value before dividing by 7. That way, week numbers turn on
> the appropriate day (in 2005, January 9th is on week 1 while January
> 10th is on week 2; whereas without the fix, week 1 would have run from
> 1st through 6th and week 2 from 7th to 13th).

OK, thanks - I have applied this fix to CVS.  It caused two test results
(date.1 and datetime.1) to change, so I also updated those two test result
files.  Perhaps if you have a moment you might check whether you agree the
changed result is, in fact, the correct one.

Bill