Dear Toon Calders,

thanks for your detailed bug report. Yes, this was a serious issue; the predicate was optimized for an accessing the index, although it was dependent on the query context. This is now fixed in the repository version 6.1.1 of BaseX:

http://basex.org/maven/org/basex/basex/6.1.1/

I've forwarded your mail to the mailing list to let others know about it as well.

All the best, Christian

On Thu, Apr 29, 2010 at 12:17 PM, Calders, T.G.K. t.calders@tue.nl wrote:

Dear BaseX developers,

First of all, many thanks for making this nice tool freely available. I use it in my Database class so the students can practice a bit with XPath and XQuery and they are all, without any exception, very enthusiastic about the tool.

During class today, however, one of the students encountered a strange query output; I reduced the example to its essence:

For the following document:

<errordoc>                 <instructor fname="Toon" sname="Calders"/>                 <lecturer fname="Toon" sname="Calders"/> </errordoc>

We ran the query “//instructor[@sname=../lecturer/@sname]” which returned an empty answer when executed with BaseX 6.1. (with previous versions it seems to work fine; e.g., 5.7).

On the other hand, the query:

let $x:=<errordoc>                 <instructor fname="Toon" sname="Calders"/>                 <lecturer fname="Toon" sname="Calders"/>

</errordoc>

return $x//instructor[@sname=../lecturer/@sname]

does return:

<instructor fname="Toon" sname="Calders"/>

Best regards, Toon Calders TU Eindhoven

___________________________

Christian Gruen Universitaet Konstanz Department of Computer & Information Science D-78457 Konstanz, Germany Tel: +49 (0)7531/88-4449, Fax: +49 (0)7531/88-3577 http://www.inf.uni-konstanz.de/~gruen