Crimson (the version issued with JDK 1.4) crashes as follows:

java.lang.InternalError: fillbuf
	at org.apache.crimson.parser.InputEntity.parsedContent
(InputEntity.java:545)
	at org.apache.crimson.parser.Parser2.content(Parser2.java:1826)
	at org.apache.crimson.parser.Parser2.maybeElement(Parser2.java:1507)
	at org.apache.crimson.parser.Parser2.content(Parser2.java:1779)
	at org.apache.crimson.parser.Parser2.maybeElement(Parser2.java:1507)
	at org.apache.crimson.parser.Parser2.content(Parser2.java:1779)
	at org.apache.crimson.parser.Parser2.maybeElement(Parser2.java:1507)
	at org.apache.crimson.parser.Parser2.content(Parser2.java:1779)
	at org.apache.crimson.parser.Parser2.maybeElement(Parser2.java:1507)
	at org.apache.crimson.parser.Parser2.content(Parser2.java:1779)
	at org.apache.crimson.parser.Parser2.maybeElement(Parser2.java:1507)
	at org.apache.crimson.parser.Parser2.content(Parser2.java:1779)
	at org.apache.crimson.parser.Parser2.maybeElement(Parser2.java:1507)
	at org.apache.crimson.parser.Parser2.parseInternal(Parser2.java:500)
	at org.apache.crimson.parser.Parser2.parse(Parser2.java:305)
	at org.apache.crimson.parser.XMLReaderImpl.parse(XMLReaderImpl.java:442)
	at net.sf.saxon.om.Builder.build(Builder.java:264)
	at net.sf.saxon.Controller.build(Controller.java:1122)
	at net.sf.saxon.Controller.transform(Controller.java:1090)
	at net.sf.saxon.Transform.processFile(Transform.java:536)
	at net.sf.saxon.Transform.doMain(Transform.java:349)
	at net.sf.saxon.Transform.main(Transform.java:64)
Exception in thread "main" 

Last few SAX events reported were:

ContentEmitter#startElement ,code,code at line 11201
characters (2)
characters (1)
End element code
characters (71)
ContentEmitter#startElement ,code,code at line 11202

The contents of the XML around this line were:

11200: <p>If the text node contains the sequence of characters
11201: <code>]]&gt;</code>, then the currently open CDATA section should be
11202: closed following the <code>]]</code> and a new CDATA section opened
11203: before the <code>&gt;</code>.</p>

This has parsed successfully in the past; the changes made to the file before 
the failure were in an unrelated part of the document. So I guess there's some 
buffer boundary condition that's been hit, perhaps the "]]" spanning the end of 
a bufferful of data while the parser was checking for "]]>".

Adding some dummy text before the paragraph above fixed the problem.

Michael Kay