Re: [xslt] Bug report: Related to EXSLT date:add( )

[Daniel Veillard <veillard redhat com>]

On Mon, Feb 28, 2011 at 10:13:57AM +0800, Daniel Veillard wrote:
> On Fri, Nov 19, 2010 at 06:37:19PM +0100, Michael Ludwig wrote:
> > money_seshu Dronamraju schrieb am 19.11.2010 um 10:20 (+0530):
> > > 
> > > Problem description:  EXSLT date:add() adds days to xs:gYearMonth/xs:gYear
> > >  incorrectly when month is January
> > > 
> > > The following 2 expressions returns incorrect date:
> > >    <xsl:value-of select="date:add( "2001-01", "P3D" )" />       -> returns
> > > 2001-01
> > >    <xsl:value-of select="date:add( "2001", "P12D" )')" />        -> returns
> > > 2001
> > > Ideally it should return   "2001-01-04" and "2001-01-13" respectively.
> > > 
> > > Root cause:
> > > 
> > > In  _exsltDateAdd(..,..) function ( libxslt/trunk/libexslt/date.c)
> > > 
> > > Because the month is January(1), "if" condition will never evaluate to true,
> > > even though the day was changed , so it never returns return type as XS_DATE
> > > 
> > > Patch: attached.
> > > 
> > > Please provide your  comments.
> > 
> > I haven't tried your patch, but here's a standalone copy/paste testcase to
> > confirm the issue:
> > 
> > <xsl:stylesheet version="1.0"
> >   xmlns:date="http://exslt.org/dates-and-times";
> >   exclude-result-prefixes="date"
> >   xmlns:xsl="http://www.w3.org/1999/XSL/Transform";>
> >   <xsl:output indent="yes"/>
> >   <xsl:template match="/">
> >     <dates-and-times>
> >       <d><xsl:value-of select="date:add( '2001-01', 'P3D' )" /></d>
> >       <d><xsl:value-of select="date:add( '2001-02', 'P3D' )" /></d>
> >       <d><xsl:value-of select="date:add( '2001-12', 'P3D' )" /></d>
> >       <d><xsl:value-of select="date:add( '2001-12', 'P30D' )" /></d>
> >       <d><xsl:value-of select="date:add( '2001-12', 'P31D' )" /></d>
> >       <d><xsl:value-of select="date:add( '2001-12', 'P32D' )" /></d>
> >     </dates-and-times>
> >   </xsl:template>
> > </xsl:stylesheet>
> > 
> > $ xsltproc exslt-date.xsl exslt-date.xsl
> > 
> > <?xml version="1.0"?>
> > <dates-and-times>
> >   <d>2001-01</d>
> >   <d>2001-02-04</d>
> >   <d>2001-12-04</d>
> >   <d>2001-12-31</d>
> >   <d>2002-01</d>
> >   <d>2002-01</d>
> > </dates-and-times>
> > 
> > January seems problematic indeed.
> 
>   Okay, by applying the patch this looks indeed better:
> 
> paphio:~/XSLT/tests/general -> cat date_add.out
> <?xml version="1.0"?>
> <dates-and-times>
>   <d>2001-01-04</d>
>   <d>2001-02-04</d>
>   <d>2001-12-04</d>
>   <d>2001-12-31</d>
>   <d>2002-01</d>
>   <d>2002-01-02</d>
>   </dates-and-times>
> </dates-and-times>
> 
>   But should '2001-12' plus 31 days areally generate "2002-01" and not
>   "2002-01-01", I'm wondering ?

  In the absence of answer I assume current status is better than
  previous so commiting this :-)

Daniel

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