title: SelectOneMenu label is "covered"
body: <p>This is probably a CSS problem, but I cannot understand the reason by myself.</p>
  
  <p>I often found some selectonemenus behaving like the one in picture:</p>
  
  <p><img src="https://i.stack.imgur.com/BBSia.png" alt="enter image description here"></p>
  
  <p>The dropdown field is "covered".
  Then I click it, select a value and... it starts displaying correctly.</p>
  
  <p>I am using Cupertino theme.</p>
  
  <p>If I analyze the generated source, here's what I find:</p>
  
  <pre><code>&lt;div class="ui-helper-hidden-accessible"&gt;
     &lt;input id="carrello:formCarrello:j_idt165_focus" name="carrello:formCarrello:j_idt165_focus" type="text"&gt;
  &lt;/div&gt;
  
  &lt;label id="carrello:formCarrello:j_idt165_label" class="ui-selectonemenu-label ui-inputfield ui-corner-all" style="width: 0px;"&gt;
     Seleziona...
  &lt;/label&gt;
  </code></pre>
  
  <p>The label has "width:0px;". If I remove it, the menu is displayed correctly.</p>
  
  <p>Good but... I DID NOT add that attribute. Why is Primefaces adding it?</p>
  
  <p><strong>EDIT</strong></p>
  
  <p>The source of the first menu:</p>
  
  <pre><code>&lt;p:selectOneMenu value="#{posController.rigaVendita.codiceIva}" effect="fade" converter="codiceIvaConverter"&gt;  
                                  &lt;f:selectItem itemLabel="Seleziona..." itemValue="" /&gt;  
                                  &lt;f:selectItems value="#{posController.codiciIva}" var="ci" itemLabel="#{ci.codice}" itemValue="#{ci}" /&gt;  
                              &lt;/p:selectOneMenu&gt;  
  </code></pre>
  
  <p>The same problem in all browser. 
  It isn't a css compatibility issue, the fault is the "0px" width attribute!</p>