Issue #2907863 by tucho, Sutharsan, Gábor Hojtsy: Prefer HTTPS protocol over HTTP when fetching translations

core/modules/locale/config/install/locale.settings.yml

@@ -5,7 +5,7 @@ javascript:
 translation:
   use_source: remote_and_local
   default_filename: '%project-%version.%language.po'
-  default_server_pattern: 'http://ftp.drupal.org/files/translations/%core/%project/%project-%version.%language.po'
+  default_server_pattern: 'https://ftp.drupal.org/files/translations/%core/%project/%project-%version.%language.po'
   overwrite_customized: false
   overwrite_not_customized: true
   update_interval_days: 0

core/modules/locale/locale.install

@@ -304,3 +304,15 @@ function locale_update_8300() {
   // the new key value collection.
   \Drupal::state()->delete('locale.translation_status');
 }
+
+/**
+ * Update default server pattern value to use https.
+ */
+function locale_update_8500() {
+  $update_url = \Drupal::config('locale.settings')->get('translation.default_server_pattern');
+  if ($update_url == 'http://ftp.drupal.org/files/translations/%core/%project/%project-%version.%language.po') {
+    \Drupal::configFactory()->getEditable('locale.settings')
+      ->set('translation.default_server_pattern', 'https://ftp.drupal.org/files/translations/%core/%project/%project-%version.%language.po')
+      ->save();
+  }
+}

core/modules/locale/locale.module

@@ -99,7 +99,7 @@ const LOCALE_TRANSLATION_USE_SOURCE_REMOTE_AND_LOCAL = 'remote_and_local';
  *
  * @see locale_translation_default_translation_server().
  */
-const LOCALE_TRANSLATION_DEFAULT_SERVER_PATTERN = 'http://ftp.drupal.org/files/translations/%core/%project/%project-%version.%language.po';
+const LOCALE_TRANSLATION_DEFAULT_SERVER_PATTERN = 'https://ftp.drupal.org/files/translations/%core/%project/%project-%version.%language.po';
 
 /**
  * The number of seconds that the translations status entry should be considered.