#157747 by dopry: the files coming from the form are arrays, and need to by casted to objects

modules/upload/upload.module

@@ -459,6 +459,7 @@ function _upload_form($node) {
     $form['files']['#theme'] = 'upload_form_current';
     $form['files']['#tree'] = TRUE;
     foreach ($node->files as $key => $file) {
+      $file = (object)$file;
       $description = file_create_url($file->filepath);
       $description = "<small>". check_plain($description) ."</small>";
       $form['files'][$key]['description'] = array('#type' => 'textfield', '#default_value' => !empty($file->description) ? $file->description : $file->filename, '#maxlength' => 256, '#description' => $description );