[324927] Do not serialize configurations that are contributed by Eclipse plug-ins.

Signed-off-by: Florian Thienel <florian@thienel.org>
diff --git a/sourceediting/tests/org.eclipse.wst.xml.vex.ui.tests/testdata/test.dtd b/sourceediting/tests/org.eclipse.wst.xml.vex.ui.tests/testdata/test.dtd
new file mode 100644
index 0000000..f246a88
--- /dev/null
+++ b/sourceediting/tests/org.eclipse.wst.xml.vex.ui.tests/testdata/test.dtd
@@ -0,0 +1,10 @@
+<!ELEMENT any ANY>
+<!ELEMENT empty EMPTY>
+<!ELEMENT section (title?, para+)>
+<!ELEMENT para (#PCDATA | emphasis)*>
+<!ELEMENT title (#PCDATA)>
+<!ELEMENT emphasis (#PCDATA)>
+
+<!-- a dummy attribute, just to make sure attribute def serialization is OK -->
+<!ATTLIST section
+	name	CDATA	#IMPLIED>
\ No newline at end of file