From 04516c12991672487b6fa4ac5c444e8501a1a2a1 Mon Sep 17 00:00:00 2001
From: Sergey Biryukov <sergeybiryukov@git.wordpress.org>
Date: Sun, 2 Sep 2018 22:08:05 +0000
Subject: [PATCH] Taxonomy: Make sure `wp_list_categories()` correctly outputs
 term name of `0`.

Props joyously, SergeyBiryukov.
Fixes #44872.

git-svn-id: https://develop.svn.wordpress.org/trunk@43605 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-includes/class-walker-category.php     |  2 +-
 .../tests/category/wpListCategories.php       | 37 +++++++++++++++----
 2 files changed, 30 insertions(+), 9 deletions(-)

diff --git a/src/wp-includes/class-walker-category.php b/src/wp-includes/class-walker-category.php
index e9975ef1af..4c155c721b 100644
--- a/src/wp-includes/class-walker-category.php
+++ b/src/wp-includes/class-walker-category.php
@@ -104,7 +104,7 @@ class Walker_Category extends Walker {
 		);
 
 		// Don't generate an element if the category name is empty.
-		if ( ! $cat_name ) {
+		if ( '' === $cat_name ) {
 			return;
 		}
 
diff --git a/tests/phpunit/tests/category/wpListCategories.php b/tests/phpunit/tests/category/wpListCategories.php
index 6d428c8204..4d75b4ac00 100644
--- a/tests/phpunit/tests/category/wpListCategories.php
+++ b/tests/phpunit/tests/category/wpListCategories.php
@@ -103,6 +103,35 @@ class Tests_Category_WpListCategories extends WP_UnitTestCase {
 		$this->assertNotContains( 'Test Cat 1', $found );
 	}
 
+	public function list_cats_callback( $cat ) {
+		if ( 'Test Cat 1' === $cat ) {
+			return '';
+		}
+
+		return $cat;
+	}
+
+	/**
+	 * @ticket 44872
+	 */
+	public function test_should_create_element_when_cat_name_is_zero() {
+		$c = self::factory()->category->create(
+			array(
+				'name' => '0',
+			)
+		);
+
+		$found = wp_list_categories(
+			array(
+				'hide_empty' => false,
+				'echo'       => false,
+			)
+		);
+
+		$this->assertContains( "cat-item-$c", $found );
+		$this->assertContains( '0', $found );
+	}
+
 	public function test_show_option_all_link_should_go_to_home_page_when_show_on_front_is_false() {
 		$cats = self::factory()->category->create_many( 2 );
 
@@ -247,14 +276,6 @@ class Tests_Category_WpListCategories extends WP_UnitTestCase {
 		$this->assertContains( "<li class='cat-item-all'><a href='" . $url . "'>All</a></li>", $found );
 	}
 
-	public function list_cats_callback( $cat ) {
-		if ( 'Test Cat 1' === $cat ) {
-			return '';
-		}
-
-		return $cat;
-	}
-
 	/**
 	 * @ticket 33460
 	 */