From 27c8977af9394716a2af7ae23617d71be1afd03c Mon Sep 17 00:00:00 2001
From: Boone Gorges <boonebgorges@git.wordpress.org>
Date: Sat, 29 Aug 2015 19:45:35 +0000
Subject: [PATCH] In `wp_list_categories()`, 'current_category' should accept
 an array of values.

This allows the 'current-cat' or 'current-cat-parent' classes to be applied
to more than one item in the list.

Props vilkatis.
Fixes #33565.

git-svn-id: https://develop.svn.wordpress.org/trunk@33804 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-includes/category-template.php         | 23 +++++++++++++------
 .../tests/category/wpListCategories.php       | 17 ++++++++++++++
 2 files changed, 33 insertions(+), 7 deletions(-)

diff --git a/src/wp-includes/category-template.php b/src/wp-includes/category-template.php
index 797d07a20f..e621067e67 100644
--- a/src/wp-includes/category-template.php
+++ b/src/wp-includes/category-template.php
@@ -461,7 +461,8 @@ function wp_dropdown_categories( $args = '' ) {
  * Display or retrieve the HTML list of categories.
  *
  * @since 2.1.0
- * @since 4.4.0 Introduced the `hide_title_if_empty` argument.
+ * @since 4.4.0 Introduced the `hide_title_if_empty` argument. The `current_category` argument was modified to
+ *              optionally accept an array of values.
  *
  * @param string|array $args {
  *     Array of optional arguments.
@@ -488,7 +489,8 @@ function wp_dropdown_categories( $args = '' ) {
  *     @type array|string $exclude_tree          Array or comma/space-separated string of term IDs to exclude, along
  *                                               with their descendants. See {@link get_terms()}. Default empty string.
  *     @type bool|int     $echo                  True to echo markup, false to return it. Default 1.
- *     @type int          $current_category      Category that should get the 'current-cat' class. Default 0.
+ *     @type int|array    $current_category      ID of category, or array of IDs of categories, that should get the
+ *                                               'current-cat' class. Default 0.
  *     @type bool         $hierarchical          Whether to include terms that have non-empty descendants.
  *                                               See {@link get_terms()}. Default true.
  *     @type string       $title_li              Text to use for the list title `<li>` element. Pass an empty string
@@ -1121,11 +1123,18 @@ class Walker_Category extends Walker {
 			);
 
 			if ( ! empty( $args['current_category'] ) ) {
-				$_current_category = get_term( $args['current_category'], $category->taxonomy );
-				if ( $category->term_id == $args['current_category'] ) {
-					$css_classes[] = 'current-cat';
-				} elseif ( $category->term_id == $_current_category->parent ) {
-					$css_classes[] = 'current-cat-parent';
+				// 'current_category' can be an array, so we use `get_terms()`.
+				$_current_terms = get_terms( $category->taxonomy, array(
+					'include' => $args['current_category'],
+					'hide_empty' => false,
+				) );
+
+				foreach ( $_current_terms as $_current_term ) {
+					if ( $category->term_id == $_current_term->term_id ) {
+						$css_classes[] = 'current-cat';
+					} elseif ( $category->term_id == $_current_term->parent ) {
+						$css_classes[] = 'current-cat-parent';
+					}
 				}
 			}
 
diff --git a/tests/phpunit/tests/category/wpListCategories.php b/tests/phpunit/tests/category/wpListCategories.php
index 92284f8f9f..56ae395a9e 100644
--- a/tests/phpunit/tests/category/wpListCategories.php
+++ b/tests/phpunit/tests/category/wpListCategories.php
@@ -45,6 +45,23 @@ class Tests_Category_WpListCategories extends WP_UnitTestCase {
 		$this->assertNotRegExp( '/class="[^"]*cat-item-' . $c2 . '[^"]*current-cat-parent[^"]*"/', $found );
 	}
 
+	/**
+	 * @ticket 33565
+	 */
+	public function test_current_category_should_accept_an_array_of_ids() {
+		$cats = $this->factory->category->create_many( 3 );
+
+		$found = wp_list_categories( array(
+			'echo' => false,
+			'hide_empty' => false,
+			'current_category' => array( $cats[0], $cats[2] ),
+		) );
+
+		$this->assertRegExp( '/class="[^"]*cat-item-' . $cats[0] . '[^"]*current-cat[^"]*"/', $found );
+		$this->assertNotRegExp( '/class="[^"]*cat-item-' . $cats[1] . '[^"]*current[^"]*"/', $found );
+		$this->assertRegExp( '/class="[^"]*cat-item-' . $cats[2] . '[^"]*current-cat[^"]*"/', $found );
+	}
+
 	/**
 	 * @ticket 16792
 	 */