Issue #1804394 by deviance, Albert Volkman: Convert file.module variables to CMI.

core/modules/file/config/file.settings.yml

+description:
+  type: 'textfield'
+  length: 128
+icon:
+  directory: 'core/modules/file/icons'
+

core/modules/file/file.field.inc

@@ -427,11 +427,12 @@ function file_field_widget_process($element, &$form_state, $form) {
 
   // Add the description field if enabled.
   if (!empty($instance['settings']['description_field']) && $item['fid']) {
+    $config = config('file.settings');
     $element['description'] = array(
-      '#type' => variable_get('file_description_type', 'textfield'),
+      '#type' => $config->get('description.type'),
       '#title' => t('Description'),
       '#value' => isset($item['description']) ? $item['description'] : '',
-      '#maxlength' => variable_get('file_description_length', 128),
+      '#maxlength' => $config->get('description.length'),
       '#description' => t('The description may be used as the label of the link to the file.'),
     );
   }

core/modules/file/file.install

@@ -232,3 +232,16 @@ function file_requirements($phase) {
 
   return $requirements;
 }
+
+/**
+* Converts default_file_main variable to config.
+*
+* @ingroup config_upgrade
+*/
+function file_update_8000() {
+  update_variables_to_config('file.settings', array(
+    'file_description_type' => 'description.type',
+    'file_description_length'=>'description.length',
+    'file_icon_directory'=>'icon.directory',
+  ));
+}

core/modules/file/file.module

@@ -1231,7 +1231,8 @@ function file_managed_file_pre_render($element) {
  *   An associative array containing:
  *   - file: A file object to which the link will be created.
  *   - icon_directory: (optional) A path to a directory of icons to be used for
- *     files. Defaults to the value of the "file_icon_directory" variable.
+ *     files. Defaults to the value of the "icon.directory"
+ *     variable.
  *
  * @ingroup themeable
  */
@@ -1270,7 +1271,8 @@ function theme_file_link($variables) {
  *   An associative array containing:
  *   - file: A file entity for which to make an icon.
  *   - icon_directory: (optional) A path to a directory of icons to be used for
- *     files. Defaults to the value of the "file_icon_directory" variable.
+ *     files. Defaults to the value of the "icon.directory"
+ *     variable.
  *
  * @ingroup themeable
  */
@@ -1290,7 +1292,7 @@ function theme_file_icon($variables) {
  *   A file entity.
  * @param $icon_directory
  *   (optional) A path to a directory of icons to be used for files. Defaults to
- *   the value of the "file_icon_directory" variable.
+ *   the value of the "icon.directory" variable.
  *
  * @return
  *   A URL string to the icon, or FALSE if an appropriate icon cannot be found.
@@ -1309,7 +1311,7 @@ function file_icon_url(File $file, $icon_directory = NULL) {
  *   A file entity.
  * @param $icon_directory
  *   (optional) A path to a directory of icons to be used for files. Defaults to
- *   the value of the "file_icon_directory" variable.
+ *   the value of the "icon.directory" variable.
  *
  * @return
  *   A string to the icon as a local path, or FALSE if an appropriate icon could
@@ -1318,7 +1320,7 @@ function file_icon_url(File $file, $icon_directory = NULL) {
 function file_icon_path(File $file, $icon_directory = NULL) {
   // Use the default set of icons if none specified.
   if (!isset($icon_directory)) {
-    $icon_directory = variable_get('file_icon_directory', drupal_get_path('module', 'file') . '/icons');
+    $icon_directory = config('file.settings')->get('icon.directory');
   }
 
   // If there's an icon matching the exact mimetype, go for it.