In topicpull, update "copy-shortdesc" template to process all @href values

[chrispy-snps]

Description

Updates topicpull processing to properly compute a topic link's description when the target topic contains a <shortdesc> containing another <xref> to a target file in a different directory.

Motivation and Context

Fixes #4244.

The code in this template has been in place for at least 13 years, as shown by the following blame link:

https://github.com/dita-ot/dita-ot/blame/49975b0660689d34178612a930a3033f47f58c83/src/main/plugins/org.dita.base/xsl/preprocess/topicpullImpl.xsl#L1251

Perhaps back then, the test for / in the @href value was because topicpull document path resolution was not as robust. It seems to work fine now. If we find a case where it doesn't, we should fix the issue instead of returning *** as the inner link text.

Once the requirement for lack of / is removed,

• The test in the third branch of the xsl:choose simplifies to true().
  • Because empty @href values are handled by the first branch, @href is always non-empty at the third branch.
  • If we also include @href values containing /, then not(contains(@href,'/')) or contains(@href,'/') simplifies to true().
• The fourth and fifth branches are never used.
• The first three branches all apply the same processing, so the xsl:choose can be simplified to just that processing.

Side note - the copy-shortdesc template processing for <xref> elements is the same as the copy-shortdesc identity template:

  <xsl:template match="*|@*|processing-instruction()" mode="copy-shortdesc">
    <xsl:copy>
      <xsl:apply-templates select="@*|text()|*|processing-instruction()" mode="#current" />
    </xsl:copy>
  </xsl:template>

except that PIs are not copied.

How Has This Been Tested?

I confirmed the fix with the #4244 testcase. I also ran the unit tests, although I don't think there is currently any test coverage of this <xref>-<shortdesc>-<xref> scenario, as I can replace it with

  <xsl:template match="*[contains(@class,' topic/xref ')]" mode="copy-shortdesc">
    <xsl:message terminate="yes">FAIL</xsl:message>
  </xsl:template>

and all tests still pass.

Type of Changes

• Bug fix (non-breaking change which fixes an issue)

Documentation and Compatibility

No documentation update is needed.

A release notes entry could be something like:

For cross-references to a topic, the target topic’s short description is processed to create a link description. When that <shortdesc> element contained another cross-reference to a file in a different directory, the second link's description would contain *** instead of the expected link text.

Checklist

• My code follows the code style of this project.
  • https://github.com/dita-ot/dita-ot/wiki/XSLT-Coding-Conventions
  • https://github.com/dita-ot/docs/wiki/coding-guidelines

[chrispy-snps]

@jelovirt - is this a good candidate for 4.1.2?