Postback form (optional 'action' attribute for html-el:form) is not working

The release notes for 1.3 mention 'Postback forms' and say that the 'action'
attribute of the form tag is now optional. This hasn't been changed in the tld
for the html-el taglib. Making that change resulted in the following NPE. Was
this feature implemented in the Struts EL taglib?

14:20:18,187 - ERROR
org.apache.catalina.core.ContainerBase.[Catalina].[example.com].[/myapp].[action]

• Servlet.service() for servlet action threw exception
  java.lang.NullPointerException
  at org.apache.struts.taglib.TagUtils.getActionMappingName(TagUtils.java:560)
  at org.apache.struts.taglib.html.FormTag.lookup(FormTag.java:755)
  at org.apache.struts.taglib.html.FormTag.doStartTag(FormTag.java:410)
  at org.apache.strutsel.taglib.html.ELFormTag.doStartTag(ELFormTag.java:396)
  at
  org.apache.jsp.WEB_002dINF.jsp.chooseAgresrelBody_jsp._jspx_meth_html_form_0(org.apache.jsp.WEB_002dINF.jsp.chooseAgresrelBody_jsp:132)
  at
  org.apache.jsp.WEB_002dINF.jsp.chooseAgresrelBody_jsp._jspService(org.apache.jsp.WEB_002dINF.jsp.chooseAgresrelBody_jsp:90)
  at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
  at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)