Dynamic values in f:validateLongRange

Question

In the code below, I'm having issues trying to dynamically set the maximum value for the long validation. I'm using apache MyFaces 1.1.1 on tomcat 5.5.12. When i use a normal number, it works, but when i try to use the expression, i get the following error:
java.lang.NullPointerException
     at org.apache.myfaces.convert.ConverterUtils.convertToLong(ConverterUtils.java:97)
public interface Sellable {
     public Long getPurchaselimit();
<h:column>
<f:facet name="header">
<h:outputText value="Quantity" />
</f:facet>
<h:inputText  value="#{q.quantity}" >
  <f:convertNumber integerOnly="true" />
  <f:validateLongRange  minimum="0" maximum="#{q.sellable.purchaselimit}" />
</h:inputText>
<h:outputText value="#{q.quantity}" rendered="#{q.sellable.purchaselimit == 1}" />
</h:column>

Answer 1

After some further investigation, i believe there might be a bug.
The code below works, where cartBean.limit returns a long. The value of q.sellable.purchaselimit is also valid and does appear properly in the h:outputText.
Any further help is appreciated.
<h:inputText id="quantity" value="#{q.quantity}" >
     <f:convertNumber integerOnly="true" />
     <f:validateLongRange minimum="0" maximum="#{cartBean.limit}" />
</h:inputText>
<h:outputText value="#{q.quantity}" rendered="#{q.sellable.purchaselimit == 1}" />
<htm:br />
<h:outputText value="#{q.sellable.purchaselimit}" />
<htm:br />
<h:outputText value="#{cartBean.limit}" />