fix bug : deleted entities crash site when in usser flag_lists

sites/all/modules/gui/materiobasemod/materio_admin.module

@@ -18,6 +18,10 @@ function materio_admin_permission() {
       'title' => t('access duplicate mails list'),
       'description' => t('access duplicate mails list.'),
     ),
+    'access missing flags list' => array(
+      'title' => t('access missing flags list'),
+      'description' => t('access missing flags list.'),
+    ),
     'materio admin fix term reference field' => array(
       'title' => t('Materio admin fix term reference field'),
       'description' => t('Materio admin fix term reference field.'),
@@ -55,6 +59,15 @@ function materio_admin_menu() {
     }
   }
 
+  if(module_exists('flag') && module_exists('flag_lists')){
+    $items['admin/people/missingflags'] = array(
+      'title' => "Missing Flags",
+      'page callback' => 'materio_missingflags',
+      'access callback' => 'user_access',
+      'access arguments' => array('access missing flags list'),
+      'type' => MENU_LOCAL_TASK
+    );
+  }
 
   // fix term ref field lost with taxonomy
   $items['admin/config/content/materio'] = array(
@@ -114,6 +127,43 @@ function materio_duplicatemails(){
   return $output;
 }
 
+
+function materio_missingflags(){
+  $flags = db_query('SELECT fcid,fid,entity_type,entity_id,uid FROM {flag_lists_content}');
+  
+  foreach ($flags as $key => $value) {
+    // $entity = entity_load($value->entity_type, array($value->entity_id));
+    $query = new EntityFieldQuery();
+    $query
+      ->entityCondition('entity_type', $value->entity_type)
+      ->propertyCondition('nid', $value->entity_id);
+    $entity = $query->execute();
+
+    if(!isset($entity['node'])){
+      $missingentities[$value->fid] = $value;
+    }
+  }
+
+  // Bail out early if there are no duplicates.
+  if (!$missingentities) {
+    return t('No missing entities in flags.');
+  }else{
+    dsm($missingentities);
+  }
+
+  // delete flags with missing entities
+  foreach ($missingentities as $fid => $value) {
+    db_delete('flag_lists_content')
+      ->condition('fcid', $value->fcid)
+      ->execute();
+    watchdog('flag_lists', t('Deleted entry @fcid from flat_lists_content', array('@fcid' => $value->fcid)));
+  }
+
+  // Turn the data we've got into markup.
+  $output = t('@count missing entities in flag lists have been cleaned', array('@count'=> count($missingentities)));
+  return $output;
+}
+
 function materio_admin_fix_termref_fields_form(){
   drupal_set_title('Fix term reference fields', PASS_THROUGH);