Remove empty tags from XML using XSLT except whitespaces

Question

I wish to remove all the blank tags from my xml using xslt, except when a tag contains a whitespace.Also there should be no impact on line breaks etc. The xml should be copied as is, except for the blank tags with no value or whitespace.

Source XML

<inRoot>
    <t1></t1>
    <t2> </t2>
    <t3>World</t3>
</inRoot>

Output I want

<inRoot>
    <t2> </t2>
    <t3>World</t3>
</inRoot>

XSLT I tried is removing t1 but is giving me a blank line in place of t1.

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:output method="xml"/>
 <xsl:strip-space elements=""/>
    <xsl:template match="/">
        <xsl:apply-templates select="*"/>
    </xsl:template>
    <xsl:template match="*">
            <xsl:if test=".!=''">
                <xsl:copy>
                  <xsl:copy-of select="@*"/>
                  <xsl:apply-templates/>
                </xsl:copy>
            </xsl:if>
    </xsl:template>
</xsl:stylesheet>

This code gives me output as

<inRoot>
    
    <t2> </t2>
    <t3>World</t3>
</inRoot>

Could anyone please advise why I am getting this extra line for t1.

Regards

Answer 1

Use the identity transformation template (in XSLT 1 and 2) or declare (in XSLT 3) <xsl:mode on-no-match="shallow-copy"/> plus the template

<xsl:template match="*[not(node())]"/>

to ensure that element nodes not having any contents/any child nodes are not copied through.