code: protected boolean processActionOverride( HttpServletRequest request, HttpServletResponse response )
          throws IOException, ServletException
      {
          // Only make this check if this is an initial (non-forwarded) request.
          //
          // TODO: performance?
          //
          PageFlowRequestWrapper wrapper = PageFlowRequestWrapper.get( request );
          if ( ! wrapper.isForwardedByButton() && ! wrapper.isForwardedRequest() )
          {
              //
              // First, since we need access to request parameters here, process a multipart request
              // if that's what we have.  This puts the parameters (each in a MIME part) behind an
              // interface that makes them look like normal request parameters.
              //
              HttpServletRequest multipartAwareRequest = processMultipart( request );
  
              for ( Enumeration e = multipartAwareRequest.getParameterNames(); e.hasMoreElements(); )
              {
                  String paramName = ( String ) e.nextElement();
  
                  if ( paramName.startsWith( ACTION_OVERRIDE_PARAM_PREFIX ) )
                  {
                      String actionPath = paramName.substring( ACTION_OVERRIDE_PARAM_PREFIX_LEN );
                      ServletContext servletContext = getServletContext();
  
                      String qualifiedAction = InternalUtils.qualifyAction( servletContext,actionPath );
                      actionPath = InternalUtils.createActionPath(request, qualifiedAction );
  
                      if ( LOG.isDebugEnabled() )
                      {
                          LOG.debug( "A request parameter overrode the action.  Forwarding to: " + actionPath );
                      }
  
                      wrapper.setForwardedByButton( true );
                      doForward( actionPath, request, response );
                      return true;
                  }
              }
          }
  
          return false;
      }
docs: The requested action can be overridden by a request parameter.  In this case, we parse the action from
  the request parameter and forward to a URI constructed from it.
  
  @param request the current HttpServletRequest
  @param response the current HttpServletResponse
  @return <code>true</code> if the action was overridden by a request parameter, in which case the request
  was forwarded.
  @throws IOException
  @throws ServletException