Attached Test case that shows issue.

Steps:

• Load welcomeICEfaces.iface
• Click on the submit button, in the logs it will show the VCL being called and a null value return for the getNewValue()

It looks like MenuRenderer.getConvertedValue(...) converts an empty string submitted value to a null. This method is called during validation.

if (uiComponent instanceof UISelectOne) {
if (newSubmittedValue == null || "".equals(newSubmittedValue))

else {
.....

I don't know what is the expected behavior but it seems to me that empty strings should not be changed to null values since the MenuRenderer is already using empty strings in its decode method.

Changing MenuRenderer.getConvertedValue(...) to avoid converting empty strings solves this issue.

With HTML forms, a lack of data entered is frequently submitted as:

form_field_name=

which means that it doesn't differentiate between no input and a string with no length. With select + option elements, we have the same issue where when an option has selected=selected, then the select is submitted as it's name = the selected option's value. If that option happens to have a value of a string with no length, then it's indistinguishable from no selection happening. As such, a string with no length is effectively a reserved sentinel value for no selection, and it's not proper application usage to take that value and re-use it for something else. In this case, the application is using it to indicate a selection of an option which it internally deems as a non-user-choice. We need to take care to avoid confusing non-selection and non-user-choice.

To fix this, we need to make use of another sentinel value to indicate this non-user-choice. Anything will do, and I have tested that a space works fine. I changed the selectItem thusly:

<f:selectItem itemValue=" " itemLabel="-" />

And also, we need to change what the bean property is initialised to, or else we'll still get a single errant ValueChangeEvent.

private String a = " ";