Changeset 51204

Timestamp:

06/22/2021 07:07:26 PM (2 years ago)

Author:

SergeyBiryukov

Message:

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.

Location:

trunk

Files:

• src/wp-includes/class-wp-walker.php (modified) (2 diffs)
• tests/phpunit/tests/walker.php (modified) (1 diff)

trunk/src/wp-includes/class-wp-walker.php

@@ -343 +343 @@
         $children_elements  = array();
         foreach ( $elements as $e ) {
-            if ( 0 == $e->$parent_field ) {
+            if ( empty( $e->$parent_field ) ) {
                 $top_level_elements[] = $e;
             } else {
@@ -413 +413 @@
 
         foreach ( $elements as $e ) {
-            if ( 0 == $e->$parent_field ) {
+            if ( empty( $e->$parent_field ) ) {
                 $num++;
             }

trunk/tests/phpunit/tests/walker.php

@@ -281 +281 @@
     }
 
+    /**
+     * @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 );
+
+    }
+
 }