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arithmetic on xs:date results in NPE
Added by Anonymous almost 20 years ago
Legacy ID: #3012002
Legacy Poster: marcvc (marcvc)
Michael, might be that you're aware of it, but I could not find it in the
"bugs" section. In certain scenarios (when evaluated at compile time?)
arithmetic operations on xs:dates (probably also xs:time and xs:dateTime) results in a
NPE. I believe this is new in Saxon 8.3 Query: xs:date("1996-04-14") -
xs:date("1996-04-15") Results in: java.lang.NullPointerException at
net.sf.saxon.value.DateTimeValue.getCurrentDateTime(DateTimeValue.java:34) at
net.sf.saxon.functions.CurrentDateTime.getImplicitTimezone(CurrentDateTime.java:70) at
net.sf.saxon.value.CalendarValue.subtract(CalendarValue.java:34) at
net.sf.saxon.value.DateValue.subtract(DateValue.java:415) at
net.sf.saxon.expr.ArithmeticExpression$DateDifference.evaluateItem(ArithmeticExpression.java:828)
at net.sf.saxon.expr.ArithmeticExpression.evaluateItem(ArithmeticExpression.java:391) at
net.sf.saxon.expr.ExpressionTool.eagerEvaluate(ExpressionTool.java:273) at
net.sf.saxon.expr.BinaryExpression.analyze(BinaryExpression.java:60) at
net.sf.saxon.expr.ArithmeticExpression.analyze(ArithmeticExpression.java:150) at
net.sf.saxon.query.XQueryExpression.<init>(XQueryExpression.java:54) at
net.sf.saxon.query.QueryParser.makeXQueryExpression(QueryParser.java:71) at
net.sf.saxon.query.QueryProcessor.compileQuery(QueryProcessor.java:162) at
net.sf.saxon.query.QueryProcessor.compileQuery(QueryProcessor.java:189) at
net.sf.saxon.query.StaticQueryContext.compileQuery(StaticQueryContext.java:183) at
net.sf.saxon.Query.doMain(Query.java:334) at net.sf.saxon.Query.main(Query.java:76)
Thanks, Marc
Legacy ID: #3012078
Legacy Poster: Michael Kay (mhkay)
Thanks for the report. I wasn't aware of this specific problem, but I was aware of a
general design problem with expressions that need access to the implicit time zone even
though they consist entirely of values. Saxon tracks the dependency of expressions on
the context, but assumes that constant values have no such dependencies, which makes
this kind of expression rather a challenge. There's already code in
DateTimeValue.currentDateTime() that attempts to deal with the absence of a Controller
and I'll patch it so it can also deal with the absence of an XPathContext. For a more
radical fix I'll await the outcome of the round of discussions that's taking place (yet
again) on the semantics of operations with and without timezones.
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