Incorrect label resolution of an option-set inside an item-set

[alansemenov]

When the first non-empty property value for an item-set is a selected option of an option-set, the title is resolved to the option's name (option_1) instead of label (My first option). Note that for the option-set itself it's resolved correctly.

    <item-set name="myItemSet">
      <label>ItemSet</label>
      <items>
        <option-set name="checkOptionSet">
          <label>Multi-selection OptionSet</label>
          <expanded>true</expanded>
          <occurrences minimum="1" maximum="1"/>
          <options minimum="1" maximum="3">
            <option name="option_1">
              <label>My first option</label>
            </option>
            <option name="option_2">
              <label>My second option</label>
            </option>
          </options>
        </option-set>
      </items>
      <occurrences minimum="1" maximum="1"/>
    </item-set>