title: p:datatable multiple select with checkboxes. Rowtoggler triggers event
body: <p>I have a datatable inside another datatable. The nested table I need to have a multiple selection checkboxes, a button to fire actionlistener and a p:rowToggler to show more data in row. The toggler and commandbutton works fine without the selection column in the table, but when I add this column the commandButton doesn't go to the backing bean, toggler on click doesn't work properly, and setSelected isn't called. Both throw a NP. I'm using 3.4.2 is this feature on newer releases only?</p>
  
  <pre><code>  SEVERE: FullAjaxExceptionHandler: An exception occurred during processing JSF ajax request. Error page '/error.xhtml' will be shown.
     java.lang.NullPointerException
  </code></pre>
  
  <p>Table</p>
  
  <pre><code>   &lt;p:dataTable id="gro" var="g" value="#{requestBean.main.childRequest}" styleClass="veaGrid" 
       paginator="true" rows="1"    paginatorTemplate="{CurrentPageReport}"   &gt; 
  
   &lt;p:column&gt;
        &lt;p:ajaxStatus &gt;  
          &lt;f:facet name="start"&gt;  
              &lt;p:graphicImage value="/resources/images/ajaxloadingbar.gif" /&gt;  
          &lt;/f:facet&gt;  
  
          &lt;f:facet name="complete"&gt;  
              &lt;h:outputText value="" /&gt;  
          &lt;/f:facet&gt;  
      &lt;/p:ajaxStatus&gt; 
       &lt;p:dataTable id="group" var="g2" value="#{g.groups}"  rowKey="#{g2.group_name}" selection="#{requestBean.selectedGroups}" &gt;
  
              &lt;p:column selectionMode="multiple" style="width:2%" /&gt;            
  
                &lt;p:column headerText="#{g.systemCd} - Groups" style="width:25%" &gt;  
                      #{g2.group_name}  
               &lt;/p:column&gt;  
               &lt;p:column style="width:2%"&gt;  
                  View Users  &lt;p:rowToggler  /&gt;   
                &lt;/p:column&gt; 
               &lt;p:rowExpansion&gt;  
  
                  &lt;p:dataTable styleClass="veaGrid" var="g3" value="#{g2.group_members}"  sortOrder="descending" 
                      paginator="true" rows="10"  
                      paginatorTemplate="{CurrentPageReport}  {FirstPageLink} {PreviousPageLink} {PageLinks} {NextPageLink} {LastPageLink} {RowsPerPageDropdown}"  
                      filteredValue="#{requestBean.filteredMembers}"&gt;
                      &lt;p:column filterBy="#{g3.first_name}"&gt;
                         &lt;h:outputText value="#{g3.first_name}"/&gt;
                      &lt;/p:column&gt; 
                      &lt;p:column filterBy="#{g3.last_name}"&gt;
                         &lt;h:outputText value="#{g3.last_name}"/&gt;
                      &lt;/p:column&gt; 
                      &lt;p:column filterBy="#{g3.signon}"&gt;
                        &lt;h:outputText value="#{g3.signon}"/&gt;
                      &lt;/p:column&gt; 
                 &lt;/p:dataTable&gt;
              &lt;/p:rowExpansion&gt;   
  
       &lt;/p:dataTable&gt; 
            &lt;center&gt;  
              &lt;p:commandButton id="continue" value="Continue"   actionListener="#{requestBean.saveGroups}"/&gt;
            &lt;/center&gt;   
       &lt;/p:column&gt;           
   &lt;/p:dataTable&gt; 
  </code></pre>