I18N: Add the `get_available_languages` filter.

Sometimes, a language file may not exist in exactly the format or location that `get_available_languages()` expects it to be in - for sites with this level of customisation, they need to be able to add their own language files to the list of those available.

Props yoavf.
Fixes #38788.


Built from https://develop.svn.wordpress.org/trunk@39235


git-svn-id: http://core.svn.wordpress.org/trunk@39175 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/l10n.php

@@ -948,6 +948,7 @@ function translate_user_role( $name ) {
  * The default directory is WP_LANG_DIR.
  *
  * @since 3.0.0
+ * @since 4.7.0 The results are now filterable with the get_available_languages filter.
  *
  * @param string $dir A directory to search for language files.
  *                    Default WP_LANG_DIR.
@@ -967,7 +968,15 @@ function get_available_languages( $dir = null ) {
 		}
 	}
 
-	return $languages;
+	/**
+	 * Filters the list of available language codes
+	 *
+	 * @since 4.7.0
+	 *
+	 * @param array $languages An array of available language codes.
+	 * @param string $dir The directory where the language files were found.
+	 */
+	return apply_filters( 'get_available_languages', $languages, $dir );
 }
 
 /**

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.7-beta3-39234';
+$wp_version = '4.7-beta3-39235';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.