Xalan-J 1 bug : XPath relational op "<=" must be numeric

[David Patow <dp...@anchorsilk.com>]

Greetings, Xalan-J Developers,
 
A bug in the XPath expression processing, I think, ...
 
According to the XPath spec, at link  <http://www.w3.org/TR/xpath#booleans>
http://www.w3.org/TR/xpath#booleans, 7th paragraph, ...
"
When neither object to be compared is a node-set and the operator is <=, <,
>= or >, then the objects are compared by converting both objects to numbers
and comparing the numbers according to IEEE 754.
"
 
If you look at file XPath.java, method lte(), it does not appear to be
performing the conversion to numeric.
 
It performs a lexical comparison, which is incorrect.
 
Thus, code like this, which is looking for no following sibling nodes OR a
following sibling with a lower @LEVEL:
 
    <xsl:when test="count(following-sibling::*)=0 or
number(following-sibling::*[1]/@LEVEL) &lt;= number(@LEVEL)">
 
fails when the follow-sibling level is 10 and the current node's level is 9,
because the lexical comparison is not the same as the numeric comparison.
 
Have fun!
 
++ David Patow
++ mailto: David_Patow@AnchorSilk.com <ma...@AnchorSilk.com> 

Re: Xalan-J 1 bug : XPath relational op "<=" must be numeric

[Gary L Peskin <ga...@firstech.com>]

> David Patow wrote:
> 
> Greetings, Xalan-J Developers,
> 
> A bug in the XPath expression processing, I think, ...
> 
> According to the XPath spec, at link
> http://www.w3.org/TR/xpath#booleans, 7th paragraph, ...
> "
> When neither object to be compared is a node-set and the operator is
> <=, <, >= or >, then the objects are compared by converting both
> objects to numbers and comparing the numbers according to IEEE 754.
> "
> 
> If you look at file XPath.java, method lte(), it does not appear to be
> performing the conversion to numeric.
> 
> It performs a lexical comparison, which is incorrect.

As I read the code, it looks fine.

XPath.lte() returns expr1.lessThanOrEqual(expr2) ? m_true : m_false

where expr1 and expr2 are both XObjects.

XObject.lessThanOrEqual() for non-node-sets returns this.num() <=
obj2.num().

This calls to num() should accomplish the numeric conversion.

If you have XML and XSLT which demonstrates this problem, please forward
the complete examples to the list.

Thanks,
Gary