From 243e75eb416657464870ea9092c8750b7221b8fc Mon Sep 17 00:00:00 2001
From: hellofromTonya <hellofromTonya@git.wordpress.org>
Date: Fri, 10 Sep 2021 15:03:57 +0000
Subject: [PATCH] Code Modernization: Fix null to non-nullable deprecation in
 `term_exists()`.

The `term_exists()` function expects a string or an integer for the `$term` parameter. It validates for integer, but not for string or `null`.

One of the pre-existing test cases, passed `null` to the function, leading to a `trim(): Passing null to parameter #1 ($string) of type string is deprecated` notice on PHP 8.1.

Fixed now by doing a cursory check on the variable at the start of the function and bowing out early in case the `$term` is `null`.

The issue was discovered via and is already covered by the `Tests_TermExists::test_term_exists_unknown()` test method.

Follow-up to [15220]. [38716].

Props jrf, hellofromTonya.
See #53635.
Built from https://develop.svn.wordpress.org/trunk@51796


git-svn-id: http://core.svn.wordpress.org/trunk@51403 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/taxonomy.php | 4 ++++
 wp-includes/version.php  | 2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/wp-includes/taxonomy.php b/wp-includes/taxonomy.php
index 4014a62655..531a6f537b 100644
--- a/wp-includes/taxonomy.php
+++ b/wp-includes/taxonomy.php
@@ -1480,6 +1480,10 @@ function unregister_term_meta( $taxonomy, $meta_key ) {
 function term_exists( $term, $taxonomy = '', $parent = null ) {
 	global $wpdb;
 
+	if ( null === $term ) {
+		return null;
+	}
+
 	$select     = "SELECT term_id FROM $wpdb->terms as t WHERE ";
 	$tax_select = "SELECT tt.term_id, tt.term_taxonomy_id FROM $wpdb->terms AS t INNER JOIN $wpdb->term_taxonomy as tt ON tt.term_id = t.term_id WHERE ";
 
diff --git a/wp-includes/version.php b/wp-includes/version.php
index b97456cec8..1633986cd2 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.9-alpha-51795';
+$wp_version = '5.9-alpha-51796';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.