epub3 sidebar title bug

[mosegontar]

I've run into an issue where I have the following markup:

    <sidebar>
      <title>Sidebar Title</title>
      <para>some text</para>
    </sidebar>

which is getting rendered as follows when running the epub3 stylesheets:

      <div class="sidebar" title="Sidebar Title" epub:type="sidebar">
        <div class="titlepage">
          <div>
            <div>
              <div class="-title"/>
            </div>
          </div>
        </div>
        <p>some text</p>
      </div>

I've tracked down the issue to what I believe is a missing prefix in the <xsl:template match="d:title" mode="sidebar.titlepage.recto.auto.mode"> template in the epub3/titlepage.templates.xsl stylesheet.

<xsl:template match="d:title" mode="sidebar.titlepage.recto.auto.mode">
<div xsl:use-attribute-sets="sidebar.titlepage.recto.style">
<xsl:call-template name="formal.object.heading">
<xsl:with-param name="object" select="ancestor-or-self::sidebar[1]"/>
</xsl:call-template>
</div>
</xsl:template>

When the formal.object.heading template is called with the object param, the value of object is grabbed from
<xsl:with-param name="object" select="ancestor-or-self::sidebar[1]"/>.

I've tested modifying the select to use the d prefix and target "ancestor-or-self::d:sidebar[1]".

This successfully produces the markup I expected:

     <div class="sidebar" title="Sidebar Title" epub:type="sidebar">
        <div class="titlepage">
          <div>
            <div>
              <div class="sidebar-title">Sidebar Title</div>
            </div>
          </div>
        </div>
        <p>some text</p>
      </div>

I've confirmed that this appears to be an issue (unless I've misunderstood) with both the 1.79.2 stylesheets available at
https://github.com/docbook/xslt10-stylesheets/releases/download/release/1.79.2/docbook-xsl-1.79.2.zip
and when building with the latest stylesheets in GitHub (I used the Dockerfile in the buildtools/ directory to build.)