The mojarra MenuRenderer contains the code below, which expects to ultimately render a String via a cloned ResponseWriter. This is a case that is currently not taken into account by the ResponseWriter "state machine". Ultimately, the component is simply requesting a writer to buffer its output, but this goes against the structured output we are looking for with D2D rendering. In this case, it means that the DOM diff will be unable to replace individual select items.

The "fix" at the moment is to take a particular strategy based on the passed-in writer:

    public ResponseWriter cloneWithWriter(Writer writer) {
        if (writer.getClass().getName().endsWith("FastStringWriter")) {
            return new BasicResponseWriter(writer, getContentType(), getCharacterEncoding());
        }

This cannot be the ultimate solution as there is no guarantee on the Class name of the writer. A better approach will be to understand the patter of ResponsWriter constructions, potentially eliminating the WriteBehindResponseWriter.



        FastStringWriter bufferedWriter = new FastStringWriter(128);
        context.setResponseWriter(writer.cloneWithWriter(bufferedWriter));
        int count = renderOptions(context, component, items);
        context.setResponseWriter(writer);
        // If "size" is *not* set explicitly, we have to default it correctly
        Integer size = (Integer) component.getAttributes().get("size");
        if (size == null || size == Integer.MIN_VALUE) {
            size = count;
        }
        writeDefaultSize(writer, size);

        RenderKitUtils.renderPassThruAttributes(context,
                                                writer,
                                                component,
                                                ATTRIBUTES,
                                                getNonOnChangeBehaviors(component));
        RenderKitUtils.renderXHTMLStyleBooleanAttributes(writer,
                                                         component);

        RenderKitUtils.renderOnchange(context, component);

        // Now, write the buffered option content
        writer.write(bufferedWriter.toString());

        writer.endElement("select");