title: woocommerce product category search filter showing other category products
body: <p>Any idea why this query is showing products inside a different parent category and it's children? <a href="http://botanicaevents.com/rentals/?s=white&amp;product_cat=floral" rel="nofollow">http://botanicaevents.com/rentals/?s=white&amp;product_cat=floral</a></p>
  
  <p>It should only show the product "White Floral Product Test"</p>
  
  <p>White this query works properly: <a href="http://botanicaevents.com/rentals/?s=white&amp;product_cat=rentals" rel="nofollow">http://botanicaevents.com/rentals/?s=white&amp;product_cat=rentals</a>
  Notice how the working string above doesn't show "White Floral Product Test"</p>
  
  <p>Here is the search form:</p>
  
  <pre><code>&lt;form role="search" method="get" id="searchform" action="http://botanicaevents.com/rentals/"&gt;
      &lt;div&gt;
          &lt;label class="screen-reader-text" for="s"&gt;Search for:&lt;/label&gt;
          &lt;input type="text" value="" name="s" id="s" placeholder="Search for products" /&gt;
          &lt;input type="hidden" name="product_cat" value="floral" /&gt;
          &lt;input type="submit" id="searchsubmit" value="Search" /&gt;
      &lt;/div&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>The only variation in the form is <code>name="product_cat" value="rentals"</code></p>