[xml] XPath mod operator problems

[Geert Kloosterman <geertk ai rug nl>]

Hi Daniel, all,

Part of this has allready been posted to the xslt list, but since the
real problem seems to be within libxml2, I'll continue here.

I can't reach the bugzilla site at the moment, so maybe this
phenomenon has allready been posted.

I've used libxml2-2.4.22 on all systems mentioned. 

Here we go.  On i386 platform I get the correct results:


    ./testXPath --expr '8 mod 3 = 2'
    Object is a Boolean : true


But on HP-UX 10.20 and linux-alpha:


    ./testXPath --expr '8 mod 3'
    Object is a number : 2

    ./testXPath --expr '8 mod 3 = 2'
    Object is a Boolean : false


Can anybody reproduce this on other platforms?
Daniel, should this test be added to the regression tests?


When I change the following lines of xpath.c (l. 4890, 4891),
xmlXPathModValues:

        tmp=arg1/arg2;
        ctxt->value->floatval = arg2 * (tmp - (double)((int)tmp));

into

        ctxt->value->floatval = fmod(arg1, arg2);

the behaviour looks correct.  But I don't know if fmod conforms
to the XPath requirements of the `mod' operator.

Geert