the || disjunction operator in semantic search breaks page
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Description

Author: info

Description:
Pages that use || in semantic searches return a blank page (0-length HTML, no
content).

This happened fairly recently on ontoworld.org.

It makes pages like http://ontoworld.org/wiki/Help:Category (an unofficial help
page) appear blank.

Yet the documentation
http://ontoworld.org/wiki/Help:Semantic_search#Wildcards_and_disjunctions says
that || is the right way to require a disjunction.

You can see it if you go to http://ontoworld.org/wiki/Special:Ask
and query for [[Born in::Dallas||Iceland]]

Remove one of the terms and it works.


Version: unspecified
Severity: major
URL: http://ontoworld.org/wiki/Special:Ask?query=[[Born in::Dallas||Iceland]]

bzimport set Reference to bz9178.
bzimport created this task.Via LegacyMar 6 2007, 6:15 AM
bzimport added a comment.Via ConduitMar 6 2007, 9:35 PM

info wrote:

On my local wiki, I get
Catchable fatal error: Object of class Title could not be converted to string in
C:\xampplite\htdocs\mediawiki\extensions\SemanticMediaWiki\includes\SMW_InlineQueries.php
on line 831

$check_titles = array_diff( $titles , array() ); // Copies the array

According to the doc at http://php.net/manual/en/function.array_diff,
array_diff() casts to string when comparing array entries, and this fails for
MediaWiki's Title objects.

I think this broke in revision 17529 when normalizeRedirects() switched from
working on article names to working on Title objects.

Maybe there's a better way to copy the $titles array with the desired behavior.
(I think array_unique() is a better function to use here and elsewhere than
array_diff() but it too casts to a string.)

Or, create a $check_title_article_ids array just with the title->getArticleID()s
and iterate through that; but the code is complex.
I think the code is also broken at line 850

		if (!array_key_exists( $id , $titles)) {

where it assumes a title's articleID is the key for title objects in an array.

A workaround is to disable redirect normalization by setting
$smwgIQRedirectNormalization = false; in the file.

mkroetzsch added a comment.Via ConduitApr 24 2007, 7:37 AM

I think I fixed this one for now (at least [[Born in::Dallas||Iceland]] works,
and I addressed the issue with title keys). Future versions will get a better
redirect handling.

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