Changeset 62034

Timestamp:

03/16/2026 09:54:06 PM (12 days ago)

Author:

SergeyBiryukov

Message:

Code Modernization: Fix "passing null to non-nullable" deprecation from previous_posts().

The esc_url() function expects to a string for $url parameter. There is no input validation within that function. The function contains a ltrim() which also expects a string. Passing null to this parameter results in Deprecated: ltrim(): Passing null to parameter #1 ($string) of type string is deprecated notice on PHP 8.1+.

Tracing the stack back, a null is being passed to it within previous_posts() when get_previous_posts_page_link() returns null (it can return a string or null).

On PHP 7.0 to PHP 8.x, an empty string is returned from esc_url() when null is passed to it. The change in this changeset avoids the deprecation notice by not invoking esc_url() when get_previous_posts_page_link() returns null and instead sets the $output to an empty string, thus maintaining the same behavior as before (minus the deprecation notice).

Adds a test to validate an empty string is returned and the absence of the deprecation (when running on PHP 8.1+).

Follow-up to [9632], [11383], [56740].

Props dd32, alexodiy.
Fixes #64864.

Location:

trunk

Files:

• src/wp-includes/link-template.php (modified) (1 diff)
• tests/phpunit/tests/link/previousPosts.php (added)

trunk/src/wp-includes/link-template.php

@@ -2650 +2650 @@
  */
 function previous_posts( $display = true ) {
-    $output = esc_url( get_previous_posts_page_link() );
+    $link   = get_previous_posts_page_link();
+    $output = $link ? esc_url( $link ) : '';
 
     if ( $display ) {