Taxonomy: In `register_taxonomy()`, return the registered taxonomy object on success, for consistency with `register_post_type()`.

Props krynes, SergeyBiryukov.
Fixes #48558.

git-svn-id: https://develop.svn.wordpress.org/trunk@47186 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/taxonomy.php

@@ -408,7 +408,7 @@ function is_taxonomy_hierarchical( $taxonomy ) {
  *     @type bool          $_builtin              This taxonomy is a "built-in" taxonomy. INTERNAL USE ONLY!
  *                                                Default false.
  * }
- * @return void|WP_Error Void on success, WP_Error object on failure.
+ * @return WP_Taxonomy|WP_Error The registered taxonomy object on success, WP_Error object on failure.
  */
 function register_taxonomy( $taxonomy, $object_type, $args = array() ) {
 	global $wp_taxonomies;
@@ -441,6 +441,8 @@ function register_taxonomy( $taxonomy, $object_type, $args = array() ) {
 	 * @param array        $args        Array of taxonomy registration arguments.
 	 */
 	do_action( 'registered_taxonomy', $taxonomy, $object_type, (array) $taxonomy_object );
+
+	return $taxonomy_object;
 }
 
 /**

tests/phpunit/tests/post/types.php

@@ -39,6 +39,13 @@ class Tests_Post_Types extends WP_UnitTestCase {
 		_unregister_post_type( 'foo' );
 	}
 
+	/**
+	 * @ticket 48558
+	 */
+	function test_register_post_type_return_value() {
+		$this->assertInstanceOf( 'WP_Post_Type', register_post_type( 'foo' ) );
+	}
+
 	/**
 	 * @ticket 31134
 	 *

tests/phpunit/tests/taxonomy.php

@@ -169,6 +169,13 @@ class Tests_Taxonomy extends WP_UnitTestCase {
 		unset( $GLOBALS['wp_taxonomies'][ $tax ] );
 	}
 
+	/**
+	 * @ticket 48558
+	 */
+	function test_register_taxonomy_return_value() {
+		$this->assertInstanceOf( 'WP_Taxonomy', register_taxonomy( 'foo', 'post' ) );
+	}
+
 	/**
 	 * @ticket 21593
 	 *