From 3e50f2861f22880ed63024f47b6659c61e9caba4 Mon Sep 17 00:00:00 2001
From: Sergey Biryukov <sergeybiryukov@git.wordpress.org>
Date: Tue, 22 Jun 2021 19:07:26 +0000
Subject: [PATCH] Code Modernization: Use a consistent check for parent items
in `WP_Walker`.
This affects the `::walk()`, `::paged_walk()`, and `::get_number_of_root_elements()` methods.
PHP 8 changes the way string to number comparisons are performed: https://wiki.php.net/rfc/string_to_number_comparison
In particular, checking if an empty string is equal to zero in PHP 8 evaluates to `false`, not `true`.
For the `WP_Walker` class, this resulted in an incorrect handling of parent items in a few methods.
By explicitly checking for an `empty()` value instead, we make sure the check works as expected in PHP 8 and earlier versions.
Follow-up to [35876], [48960], [49043], [49076].
Props sunxiyuan, aristath, SergeyBiryukov.
Fixes #53474.
git-svn-id: https://develop.svn.wordpress.org/trunk@51204 602fd350-edb4-49c9-b593-d223f7449a82
---
src/wp-includes/class-wp-walker.php | 4 ++--
tests/phpunit/tests/walker.php | 30 +++++++++++++++++++++++++++++
2 files changed, 32 insertions(+), 2 deletions(-)
diff --git a/src/wp-includes/class-wp-walker.php b/src/wp-includes/class-wp-walker.php
index 13c0b23429..c76451cd94 100644
--- a/src/wp-includes/class-wp-walker.php
+++ b/src/wp-includes/class-wp-walker.php
@@ -342,7 +342,7 @@ class Walker {
$top_level_elements = array();
$children_elements = array();
foreach ( $elements as $e ) {
- if ( 0 == $e->$parent_field ) {
+ if ( empty( $e->$parent_field ) ) {
$top_level_elements[] = $e;
} else {
$children_elements[ $e->$parent_field ][] = $e;
@@ -412,7 +412,7 @@ class Walker {
$parent_field = $this->db_fields['parent'];
foreach ( $elements as $e ) {
- if ( 0 == $e->$parent_field ) {
+ if ( empty( $e->$parent_field ) ) {
$num++;
}
}
diff --git a/tests/phpunit/tests/walker.php b/tests/phpunit/tests/walker.php
index 20b91df445..ea3ce16757 100644
--- a/tests/phpunit/tests/walker.php
+++ b/tests/phpunit/tests/walker.php
@@ -280,6 +280,36 @@ class Tests_Walker extends WP_UnitTestCase {
}
+ /**
+ * @ticket 53474
+ */
+ function test_multiple_items_non_numeric_parent() {
+
+ $items = array(
+ (object) array(
+ 'id' => 1,
+ 'parent' => '',
+ ),
+ (object) array(
+ 'id' => 2,
+ 'parent' => '',
+ ),
+ );
+ $output = $this->walker->walk( $items, 0 );
+
+ $this->assertSame( 2, $this->walker->get_number_of_root_elements( $items ) );
+ $this->assertSame( '<li>1</li><li>2</li>', $output );
+
+ $output = $this->walker->paged_walk( $items, 0, 1, 1 );
+
+ $this->assertSame( '<li>1</li>', $output );
+
+ $output = $this->walker->paged_walk( $items, 0, 2, 1 );
+
+ $this->assertSame( '<li>2</li>', $output );
+
+ }
+
}
class Walker_Test extends Walker {