%description:
External entities declared within the DOCTYPE are substituted.

Unfortunately, elements within the included file cannot not be gotten to work, due to problems in libXML2...

THIS TEST DOES NOT PASS WITH EXPAT -- IT DOES NOT SUPPORT DTD VALIDATION.

%file: test.xml
<?xml version="1.0"?>
<!DOCTYPE foo [
  <!ELEMENT foo (#PCDATA)>
  <!ENTITY greeting SYSTEM "greeting.txt">
]>
<foo>&greeting;</foo>

%file: greeting.txt
Hello!

%activity:
cXMLElement *node = getEnvir()->getXMLDocument("test.xml");
EV << node->getXML();

%contains: stdout
<foo>Hello!

</foo>