Undefined variable

A reference no binding in scope declares is static error XPST0008, and the processor refuses the whole stylesheet. A local xsl:variable or xsl:param reaches only the siblings after it and what they hold, so one declared inside an xsl:if is gone at its closing tag. Correct the name, move the declaration up, or make the value an xsl:param.

Incorrect:

<xsl:template match="/">
  <xsl:param name="title"/>
  <xsl:if test="$title">
    <xsl:variable name="heading" select="upper-case($title)"/>
  </xsl:if>
  <h1>
    <xsl:value-of select="$heading"/>
  </h1>
</xsl:template>

Correct:

<xsl:template match="/">
  <xsl:param name="title"/>
  <xsl:variable name="heading" select="upper-case($title)"/>
  <xsl:if test="$title">
    <h1>
      <xsl:value-of select="$heading"/>
    </h1>
  </xsl:if>
</xsl:template>

In a module that may take globals from outside the linted files (a library no entry stylesheet holds, or one using a package or an unlinted module), a name no local binding declares is left alone.