title: PrimeFaces 5 Calendar: incoherent behaviour with and without TimePicker
body: <p>I have <strong>two calendars:</strong> <code>&lt;p:calendar required="true" mask="true"&gt;</code> with a default date (current date). One has <strong>date/time pattern</strong> and the other has <strong>date pattern only</strong>.</p>
  
  <p><strong>While testing invalid cases</strong>, when inputting invalid dates (such as '33/33/3333' or '33/33/3333 33:33') or when leaving the field blank or incomplete, <strong>PrimeFaces shows different behaviour depending on the pattern:</strong></p>
  
  <ul>
  <li><p>In the <strong>date only calendar</strong>, PrimeFaces nicely shows the expected error message in a growl, and leaves the field as it was typed.</p></li>
  <li><p>In the <strong>date/time calendar</strong>, PrimeFaces reverts the field to the last valid entered date, and shows no growl.</p></li>
  </ul>
  
  <p><strong>Is there a way to make both calendars behave the same way?</strong> If possible, I'd like to show the growl AND revert the field to the last valid value.</p>
  
  <p>Code:</p>
  
  <pre><code>&lt;p:calendar
     id="calDtInicial"
     value="#{cadastrar_contrato.dtInicial}"
     maxlength="10" pattern="dd/MM/yyyy HH:mm"
     mask="true" required="true" locale="pt"
  &gt;
      &lt;f:convertDateTime pattern="dd/MM/yyyy HH:mm" /&gt;
      &lt;f:validator validatorId="sgrp.DateValidator" /&gt;
      &lt;p:ajax event="dateSelect" global="false"
              update="calDtInicial calDtFinal" /&gt;
      &lt;p:ajax event="change" global="false"
              update="calDtInicial calDtFinal :theForm:growl" /&gt;
  &lt;/p:calendar&gt;
  </code></pre>
  
  <p>-</p>
  
  <pre><code>&lt;p:calendar
     id="calDtFinal"
     value="#{cadastrar_contrato.dtFinal}"
     maxlength="10" pattern="dd/MM/yyyy"
     mask="true" required="true" locale="pt"
  &gt;
      &lt;f:convertDateTime pattern="dd/MM/yyyy" /&gt;
      &lt;f:validator validatorId="sgrp.DateValidator" /&gt;
      &lt;p:ajax event="dateSelect" global="false"
              update="calDtInicial calDtFinal" /&gt;
      &lt;p:ajax event="change" global="false"
              update="calDtInicial calDtFinal :theForm:growl" /&gt;
  &lt;/p:calendar&gt;
  </code></pre>
  
  <p>PrimeFaces 5, JSF 2.1.</p>