title: Advanced Custom Fields repeater delete_post_meta hooks passing the wrong meta
body: <p>I'm trying to run some additional functions when updating and deleting ACF custom post meta, ACF version 4.3.8. The ACF field type is a repeater with several rows. When I delete one of these rows, I'm getting the wrong $meta_key passed to my hook: </p>
  
  <pre><code>&lt;?php
  
  class My_Consultant_Save_Post {
  
      function __construct() {
  
          add_action( 'delete_post_meta', array ( $this, 'delete_consultant_meta_connections'), 10, 4 );
  
      }
  
      public function delete_consultant_meta_connections( $meta_id, $post_id, $meta_key, $_meta_value ) {
  
          echo 'post_id';
          var_dump($post_id);
  
          echo 'meta_key';
          var_dump($meta_key);
  
          echo 'current value of meta, before deleting';
          $current = get_post_meta($post_id, $meta_key);
          var_dump($current); 
  
          die;
  
      }
  }
  
  $my_consultant_update = new My_Consultant_Save_Post();
  </code></pre>
  
  <p>see <a href="https://core.trac.wordpress.org/browser/tags/4.0/src/wp-includes/meta.php#L293" rel="nofollow">delete_postmeta</a> function, and the action <a href="https://core.trac.wordpress.org/browser/tags/4.0/src/wp-includes/meta.php#L368" rel="nofollow">delete_post_meta</a></p>
  
  <p>actually it appears to be passing the $meta_key of the last row entry I have in the field group's repeater field, and definitely not one that I deleted from the front-end post editor's acf remove row button.</p>
  
  <p>Any ideas why the hook is not returning the meta_key of the actual meta I tried to delete?</p>