GWT Designer crash/failure in case of <ui:with> + <ui:attributes>

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Java class:

public class MyConverter {

    private String fmt;

    @UiConstructor
    public MyConverter(String fmt) {
        this.fmt = fmt;
    }

    public void setFmt(String value) {
        this.fmt = value;
    }

    public String getFmt() {
        return fmt;
    }
}

2. In ui.xml file:

<ui:with type="com.xxx.MyConverter" field="conv">
  <ui:attributes fmt="aaa" />
</ui:with> 

What is the expected output? What do you see instead?

It must open GWT Designer in design mode, but instead it crashes with:

java.lang.NullPointerException
    at com.google.gdt.eclipse.designer.uibinder.parser.UiBinderRenderer$3.invoke(UiBinderRenderer.java:132)
    at com.sun.proxy.$Proxy5798.handle(Unknown Source)


What version of the product are you using? On what operating system?

GWT Designer: 3.1.2.r42x201307151442 
Google Plugin for Eclipse 4.2  3.4.1.v201309130745-rel-r42


Please provide any additional information below.

The same code is compiled successfully by GWT and working in runtime without 
any problems.

Original issue reported on code.google.com by [email protected] on 10 Oct 2013 at 6:36