Node set predicate not working

[jcavalieri]

Hi,

I'm upgrading Ruby from 2.4.5 to 2.6.5 and the rexml behavior seems to have changed. We actually had some xpaths that were wrong that were working with the previous version. However, in correcting them I'm seeing this issue:

I expect the following example to return just one node.

xml_string = <<EOF
<div>
  <div>
    <test>1</test>
    <test>2</test>
  </div>
  <div>
    <test>1</test>
    <test>2</test>
  </div>
</div>
EOF

xml_doc = REXML::Document.new(xml_string)

nodes = REXML::XPath.match(xml_doc, '(/div/div/test[1])[1]')

It returns two nodes though.

>nodes.count
=> 2

> nodes.map(&:text)
=> ["1", "1"]

From my understanding placing an xpath subexpression in this (...)[1] should only return the first from the node set.

-John

[jcavalieri]

I just test with 2.4.5 and I get the result that I expect.

> nodes.count
=> 1

[jcavalieri]

It also appears to work with 2.5.

[jcavalieri]

appears to be broken in 2.7 as well

[kou]

Thanks for your report.
This is a bug. This should be fixed.