Labels not displaying correctly when using xf:output in a xf:label in an xf:itemset on a xf:select1 with @appearance="minimal"

xf:itemset can be used with xf:select1 to specify a list of choices that originate from the instance data. Typical usage is like this:

<xf:select1 ref="a" appearance="minimal">
  <xf:label>Select</xf:label>
  <xf:itemset nodeset="../b">
    <xf:label ref="." />
    <xf:value value="." />
  </xf:itemset>
</xf:select1>

But it's also possible to place xf:output controls in the label, to create more complex output:

<xf:select1 ref="a" appearance="minimal">
  <xf:label>Select</xf:label>
  <xf:itemset nodeset="../b">
    <xf:label>
      <xf:output ref="." />
    </xf:label>
    <xf:value value="." />
  </xf:itemset>
</xf:select1>

Currently, the display of the label is the full mark-up that lies between the opening and closing tags of xf:label. Sample code is available in test 4 in the select1 itemset test.