resteasy.plugins.providers.multipart.HeaderFlushedOutputStream should flush headers only once

It seems HeaderFlushedOutputStream is writing headers to response every time. This is the reason why resteasy.plugins.providers.InputStreamProvider is writing headers before every single byte with multipart/form-data output media type. Imho HeaderFlushedOutputStream should write headers only once.

Suggested fix: add a flag to HeaderFlushedOutputStream
<pre>
private MultivaluedMap<String, Object> headers;
+ private boolean headersFlushed;
private OutputStream stream;

/* ... */

protected void flushHeaders() throws IOException
{
+ if (headersFlushed)
+ return;
RuntimeDelegate delegate = RuntimeDelegate.getInstance();

for (String key : headers.keySet())
{
List<Object> objs = headers.get(key);
for (Object obj : objs)
{
String value;
RuntimeDelegate.HeaderDelegate headerDelegate = delegate.createHeaderDelegate(obj.getClass());
if (headerDelegate != null)

{ value = headerDelegate.toString(obj); }

else

{ value = obj.toString(); }

stream.write(key.getBytes());
stream.write(": ".getBytes());
stream.write(value.getBytes());
stream.write("\r\n".getBytes());
}
}
stream.write("\r\n".getBytes());

+ headersFlushed = true;
}
</pre>

The issue came up with the following example.

POJO:
<pre>
public class MyBean {
@FormParam("someBinary")
@PartType(MediaType.APPLICATION_OCTET_STREAM)
private InputStream someBinary;

/* ... */
}
</pre>

Service:
<pre>
@GET
@Produces(MediaType.MULTIPART_FORM_DATA)
public @MultipartForm
MyBean createMyBean()

{ logger.debug("started"); MyBean myBean = new MyBean(); myBean.setSomeBinary(new ByteArrayInputStream("bla".getBytes())); /* ... */ return myBean; }

</pre>

part of output:
--f231sldkxx11
Content-Length: -1
Content-Disposition: form-data; name="someBinary"
Content-Type: application/octet-stream

bContent-Length: -1
Content-Disposition: form-data; name="someBinary"
Content-Type: application/octet-stream

lContent-Length: -1
Content-Disposition: form-data; name="someBinary"
Content-Type: application/octet-stream

a

As you can see "bla" is written in 3 parts with full headers of every byte. With the above mentioned fix the result get to normal:
--f231sldkxx11
Content-Length: -1
Content-Disposition: form-data; name="someBinary"
Content-Type: application/octet-stream

bla