Now all modules are in core modules folder

modules/diff/includes/upload.inc

@@ -0,0 +1,47 @@
+<?php
+
+/**
+ * @file
+ * Implementation of hook_diff() for file attachments.
+ */
+
+/**
+ * Implementation of hook_diff() for file attachments.
+ */
+function upload_diff($old_node, $new_node) {
+  $result = array();
+  $old_files = array();
+  if (isset($old_node->files)) {
+    foreach ($old_node->files as $file) {
+      $old_files[] = $file->filename;
+    }
+  }
+  $new_files = array();
+  if (isset($new_node->files)) {
+    foreach ($new_node->files as $key => $file) {
+      if (is_array($file)) {
+        // During editing the files are stored as arrays, not objects.
+        if ($file['remove']) {
+          // It looks better if a blank line is inserted for removed files.
+          $new_files[] = '';
+        }
+        else {
+          $new_files[] = $file['filename'];
+        }
+      }
+      else {
+        $new_files[] = $file->filename;
+      }
+    }
+  }
+  $result['attachments'] = array(
+    '#name' => t('Attachments'),
+    '#old' => $old_files,
+    '#new' => $new_files,
+    '#weight' => 30,
+    '#format' => array(
+      'show_header' => FALSE,
+    )
+  );
+  return $result;
+}