Primefaces validate cell editing values - validation

Question

I have a datatable, where I add rows dynamically (a button click), and let users edit those rows with primefaces cell editing.
I want to add validation for the cells, however, the validation does not occur when the input texts (in the cell) are pristine.
In order for the validation to work, the user have to actually write something in the input text (make it dirty), then deletes it, only then the validation (required for this case) will be kicked-in.
example code:
<f:view>
<p:growl autoUpdate="true"/>
<h:form>
<p:commandButton value="add row" update="table" action="#{myBean.addRow}"/>
<p:dataTable value="#{myBean.users}" var="var" id="table" editMode="cell" editable="true">
<p:column headerText="Quantity">
<p:cellEditor>
<f:facet name="output">
<h:outputText value="#{var.name}"/>
</f:facet>
<f:facet name="input">
<p:inputText value="#{var.name}" required="true">
<f:validateRequired />
</p:inputText>
</f:facet>
</p:cellEditor>
</p:column>
</p:dataTable>
<p:commandButton value="submit" action="#{myBean.submit}"/>
</h:form>
</f:view>
Using primefaces 5.3 and JSF 2.2.
Update:
This bug is fixed since version 6.2
https://github.com/primefaces/primefaces/issues/2512