<document source="test data">
<paragraph>
A substitution definition defined using an if whose last element isn't #PCDATA.
<system_message level="1" line="3" source="test data" type="INFO">
<paragraph>
No directive entry for "if" in module "Text::Restructured::Directive".
Trying "if" as canonical directive name.
<substitution_definition names="sub">
Text ends with \n\
<emphasis>
emphasis