Taxonomy: Prevent wp_list_categories() from producing not well-nested output if hide_title_if_empty is true.

Props chesio.
Fixes #38839. See #33460.

git-svn-id: https://develop.svn.wordpress.org/trunk@39280 602fd350-edb4-49c9-b593-d223f7449a82

tests/phpunit/tests/category/wpListCategories.php

@@ -265,6 +265,22 @@ class Tests_Category_WpListCategories extends WP_UnitTestCase {
 		$this->assertContains( '<li class="categories">Categories', $found );
 	}
 
+	/**
+	 * @ticket 38839
+	 */
+	public function test_hide_title_if_empty_should_not_output_stray_closing_tags() {
+		$cat = self::factory()->category->create();
+
+		$found = wp_list_categories( array(
+			'echo' => false,
+			'show_option_none' => '',
+			'child_of' => 1,
+			'hide_title_if_empty' => true,
+		) );
+
+		$this->assertNotContains( '</ul></li>', $found );
+	}
+
 	/**
 	 * @ticket 12981
 	 */