Allows category and product to share a same base in woocommerce.

function.php

<?php
add_filter('request', function( $request ) {
  $tax_qv = 'product_cat';
  $cpt_name = 'product';

  if(!empty( $request[$tax_qv])) {
    $slug = basename($request[$tax_qv]);

    // if this would generate a 404
    if(!get_term_by('slug', $slug, $tax_qv)) {
      // set the correct query vars
      $request['name'] = $slug;
      $request['post_type'] = $cpt_name;
      unset($request[$tax_qv]);
    }
  }

  return $request;
});