[Xapian-devel] opensearch template

[Olly Betts]

I've just noticed the Omega "opensearch" template seems to lack escaping
for URLs in <link> tags:

$httpheader{Content-Type,application/xml}<?xml version="1.0"?>
  <rss version="2.0" xmlns:openSearch="http://a9.com/-/spec/opensearchrss/1.0/">
    <channel>
      <title>Xapian search results</title>
      <link>$env{SCRIPT_NAME}?DB=$dbname&amp;P=$html{$query}</link>
      <description>Search results for "$html{$query}" at xapian.org</description>
      <language>en</language>
      <copyright>(C)2005, Xapian.org</copyright>
      <openSearch:totalResults>$msize</openSearch:totalResults>
      <openSearch:startIndex>$add{topdoc,1}</openSearch:startIndex>
      <openSearch:itemsPerPage>$hitsperpage</openSearch:itemsPerPage>
$hitlist{
      <item>
        <title>$html{$or{$field{title},$field{caption}}}</title>
        <link>$field{url}</link>
        <description>$highlight{$field{sample},$terms,&lt;strong&gt;,&lt;/strong&gt;}$if{$field{sample},...}</description>
      </item>}
    </channel>
  </rss>

Surely $field{url} needs some sort of escaping?  Also, we aren't
escaping $env{SCRIPT_NAME} or $dbname in the <channel>'s <link> tag.

Sadly, the opensearch spec doesn't really seem cover the format of
URLs in <link> tags, but the "&amp;" in the <channel>'s <link> makes
me suspect that $html{ } is the right answer.

But reading the spec, it does say that any HTML in the description tag
should be escaped once, or enclosed as CDATA:

http://opensearch.a9.com/docs/devfaq.jsp#html

Since we seem to be using RSS instead of ATOM, I think that means we
need a $html{ } around the contents of the description tag.

Cheers,
    Olly