title: undefined method `stringify_keys!' for "":String when using meta_search
body: <p>This is my _search_box.html.erb file</p>
  
  <pre><code>&lt;%= form_tag "/catalog/search", :method =&gt; "get" do %&gt;
    &lt;%= text_field_tag :q %&gt; 
    &lt;%= submit_tag 'Search' %&gt;
  &lt;% end %&gt;
  </code></pre>
  
  <p>which is rendered in <code>search.html.erb</code>:</p>
  
  <pre><code>&lt;%= render :partial =&gt; 'search_box' %&gt;
  &lt;% if @products %&gt;
      &lt;%= render(:partial =&gt; "products") %&gt;
  &lt;% end %&gt;
  </code></pre>
  
  <p>And this is my <code>search</code> method for the <code>CatalogController</code> class:</p>
  
  <pre><code>  def search
      @search = Product.search(params[:q].to_s)
      @products = @search.all
      unless @products.size &gt; 0
        flash.now[:notice] = "No results."
      end
    end
  </code></pre>
  
  <p>I get this error when I access <code>/catalog/search</code></p>
  
  <pre><code>NoMethodError in CatalogController#search
  
  undefined method `stringify_keys!' for "":String
  </code></pre>
  
  <p>I am using <code>meta_search</code> gem for the search.</p>
  
  <p>What is happening?</p>