Eliminate line-breaks with XSLT 2.0 analyze-string - xslt-2.0

Question

I use the XSLT 2.0 element analyze-string in a stylesheet that transforms XML to HTML; specifically, I use it to convert string encoding for subscripts in chemical formulae to HTML subscripts. Therefore, the result is a string, to go in a p or td element, with embedded mark-up.
The transformation is supposed to produce output like H2O but in fact inserts a line-break in the HTML:
H
<sub>2</sub>O
and this break is (correctly) interpreted by the browser as a space:
H
2O
which is ugly.
Is there a way to remove the line-break? I've tried putting the whole analyze-string element on one line and that doesn't work.
The input would be something like
<OrdinaryStructralFormula>H$_2$O</OrdinaryStructuralFormula>
for a simple case and
<OrdinaryStructralFormula>C$_2$OH$_5$$^-</OrdinaryStructuralFormula>
for a more-complicated one. Note that the subscript pattern can match multiple times in the general case and can be either in the middle or at the end of the string. The pattern also has to match and eliminate any notation for charge: the $^- bit at the end of the second example.
The XSLT processor is Saxon 9.4 and the XSLT template follows.
<xsl:template name="formula">
<xsl:param name="formula"/>
<xsl:if test="$formula">
<xsl:variable name="f" select="translate($formula, '$', '')"/>
<xsl:analyze-string select="$f" regex="(_)(\d+)|(\^)\d*\+|(\^)\d*\-">
<xsl:matching-substring>
<xsl:if test="regex-group(1)='_'">
<sub><xsl:value-of select="regex-group(2)"/></sub>
</xsl:if>
</xsl:matching-substring>
<xsl:non-matching-substring>
<xsl:value-of select="."/>
</xsl:non-matching-substring>
</xsl:analyze-string>
</xsl:if>
</xsl:template>

Answer 1

I cannot reproduce the reported result.
This transformation (which is what you should have given us, but you only provided a template):
<xsl:stylesheet version="2.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output omit-xml-declaration="yes" indent="yes"/>
<xsl:template match="/">
<xsl:call-template name="formula">
<xsl:with-param name="formula" select="/*"/>
</xsl:call-template>
</xsl:template>
<xsl:template name="formula">
<xsl:param name="formula"/>
<xsl:if test="$formula">
<xsl:variable name="f" select="translate($formula, '$', '')"/>
<xsl:analyze-string select="$f" regex="(_)(\d+)|(\^)\d*\+|(\^)\d*\-">
<xsl:matching-substring>
<xsl:if test="regex-group(1)='_'">
<sub><xsl:value-of select="regex-group(2)"/></sub>
</xsl:if>
</xsl:matching-substring>
<xsl:non-matching-substring>
<xsl:value-of select="."/>
</xsl:non-matching-substring>
</xsl:analyze-string>
</xsl:if>
</xsl:template>
</xsl:stylesheet>
when applied on the following XML document with Saxon 9.1.05:
<formula>H$_2$O</formula>
produces the wanted, correct result:
H<sub>2</sub>O
When the same transformation is applied on the second XML document:
<OrdinaryStructuralFormula>C$_2$OH$_5$$^-</OrdinaryStructuralFormula>
Again the wanted correct result is produced:
C<sub>2</sub>OH<sub>5</sub>
Do note: I ran the same transformations with two other XSLT 2.0 processors: XQSharp (XMLPrime) and AltovaXML (XML-SPY) and got exactly the same, correct results.