Filedownload.save does not work with piped streams

[siepkes]

The Filedownload.save method does not work when supplying it with a PipedInputStream.

The following example (see also zkfidle) does not work. The download dialog will simply never appear. There is no error logged whatsoever:

<zk>
	<zscript><![CDATA[
	import org.zkoss.zul.Filedownload;
	import java.io.InputStream;
	import org.zkoss.lang.Strings;
	import java.io.PipedInputStream;
	import java.io.PipedOutputStream;	

	void download() throws Exception {

		final PipedOutputStream pipedOutputStream = new PipedOutputStream();
		final PipedInputStream pipedInputStream = new PipedInputStream(pipedOutputStream);
			
		Thread outputThread = new Thread(new Runnable() {
			public void run() {
				pipedOutputStream.write(new byte[] { 0x1, 0x2, 0x3, 0xf } );
   			}
				
		});
		outputThread.start();		
						
		Filedownload.save(pipedInputStream, "application/xml", "test.xml");
		
		outputThread.join();
	}
	]]></zscript>
	<button label="download" onClick="download()">
	</button>
</zk>