attribute value quoting bug in Trang?

Hi,

I typed in the example of annotations in the compact syntax on pages 218
and 219 of Eric van der Vlist's _RELAX NG_ book and ran trang-20030619
on it to see the XML syntax equivalent (which appears on page 218,
BTW).  The .rng output was not well-formed XML because of a badly quoted
attribute value.

The relevant part of the .rnc input is right near its start:

  namespace ann = "http://dyomedea.com/examples/ns/annotations"

  [
     ann:attribute = 'Annotation as foreign attribute for "grammar"'
     ann:element [ 'Initial annotation as foreign element for "grammar"' ]
  ]
  grammar {
  # ...

Note that the ann:attribute attribute's value is delimited by single
quotes and contains double quotes.

Here's the beginning of the corresponding .rng output:

  <?xml version="1.0" encoding="UTF-8"?>
  <grammar ann:attribute="Annotation as foreign attribute for "grammar""
           xmlns:ann="http://dyomedea.com/examples/ns/annotations"
           xmlns="http://relaxng.org/ns/structure/1.0">
    <ann:element>Initial annotation as foreign element for "grammar"</ann:element>

Whoops -- the value of the ann:attribute attribute is now delimited by
double quotes, but still also contains raw double quotes (as opposed to,
say, ``&quot;'' character entity references).

This behavior might be a result of some code in
com/thaiopensource/relaxng/output/common/XmlWriter.java,

  public void attribute(String name, String value) {
    if (!inStartTag)
      throw new IllegalStateException("attribute outside of start-tag");
    write(' ');
    write(name);
    write('=');
    write('"');
    data(value);
    write('"');
  }

which isn't doing anything to ``escape double quotes'' in the value its
given.


  -James Miller