title: Grails custom tag doesn't work with <g:link params>
body: <p>I have in my GSP page a <code>&lt;g:link action="test" params='["present": "yes"]'</code> tag which, when clicked, sends me to a URL ending with <code>/test?present=yes</code>.</p>
  
  <p>If I define this custom tag lib:</p>
  
  <pre><code>class HelperTagLib {
      static defaultEncodeAs = 'html'
  
      static returnObjectForTags = ['passthrough']
  
      def passthrough = { Map attrs, Object body -&gt;
          return attrs
      }
  }
  </code></pre>
  
  <p>and add it to the tag, <code>&lt;g:link action="test" params='${passthrough(["present": "yes"])}'</code>, suddenly my URL ends with <code>/test</code>, completely losing the params.</p>
  
  <p>Why does this happen and how can I work around it?</p>