title: Does spring form taglib disabled attribute really have to resolve to a string?
body: <p>I've been playing around with the spring form taglib lately and came across a fairly disturbing phenomenon.</p>
  
  <pre><code>&lt;form:select path="whatever" disabled="${true}"&gt;
  </code></pre>
  
  <p>Will render a select element that is NOT disabled</p>
  
  <pre><code>&lt;form:select path="whatever" disabled="${'true'}"&gt;
  </code></pre>
  
  <p>Will render a select element that IS disabled.</p>
  
  <p>This indicates to me that the tag expects a string in that attribute and is refusing to coerce any boolean values (possibly checking the type first).</p>
  
  <p>The impact is that I'm unable to do something like <code>&lt;form:select path="whatever" disabled="${someOtherfield.selectedId != -1}" /&gt;</code> which is something that happens fairly often in our system.</p>
  
  <p>Am I simply missing some part of the form taglibs functionality?  Is this a legitimate design decision?  A defect?</p>