From c2d8b48d972608c1d1eb7438793e1fba19d6788c Mon Sep 17 00:00:00 2001
From: Sergey Biryukov <sergeybiryukov.ru@gmail.com>
Date: Fri, 25 Feb 2022 13:48:00 +0000
Subject: [PATCH] Code Modernization: Check the return type of `wp_parse_url()`
 in `wp_mail()`.

As per the PHP manual:
> If the `component` parameter is omitted, an associative array is returned.
> If the `component` parameter is specified, `parse_url()` returns a string (or an int, in the case of `PHP_URL_PORT`) instead of an array. If the requested component doesn't exist within the given URL, `null` will be returned.

Reference: [https://www.php.net/manual/en/function.parse-url.php#refsect1-function.parse-url-returnvalues PHP Manual: parse_url(): Return Values]

In PHP 8.1, if the home URL does not have a "host" component, it would lead to a `substr(): Passing null to parameter #1 ($string) of type string is deprecated` notice.

Changing the logic around and adding validation for the return type value of `wp_parse_url()` prevents that.

Follow-up to [48601], [51606], [51622], [51626], [51629], [51630].

Props dennisatyoast, jrf.
See #54730.
Built from https://develop.svn.wordpress.org/trunk@52799


git-svn-id: http://core.svn.wordpress.org/trunk@52388 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/pluggable.php | 14 +++++++++-----
 wp-includes/version.php   |  2 +-
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/wp-includes/pluggable.php b/wp-includes/pluggable.php
index ffcd2bdcc3..fdbfdea250 100644
--- a/wp-includes/pluggable.php
+++ b/wp-includes/pluggable.php
@@ -378,12 +378,16 @@ if ( ! function_exists( 'wp_mail' ) ) :
 		 */
 		if ( ! isset( $from_email ) ) {
 			// Get the site domain and get rid of www.
-			$sitename = wp_parse_url( network_home_url(), PHP_URL_HOST );
-			if ( 'www.' === substr( $sitename, 0, 4 ) ) {
-				$sitename = substr( $sitename, 4 );
-			}
+			$sitename   = wp_parse_url( network_home_url(), PHP_URL_HOST );
+			$from_email = 'wordpress@';
 
-			$from_email = 'wordpress@' . $sitename;
+			if ( null !== $sitename ) {
+				if ( 'www.' === substr( $sitename, 0, 4 ) ) {
+					$sitename = substr( $sitename, 4 );
+				}
+
+				$from_email .= $sitename;
+			}
 		}
 
 		/**
diff --git a/wp-includes/version.php b/wp-includes/version.php
index c12126b577..30a6e6632b 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.0-alpha-52798';
+$wp_version = '6.0-alpha-52799';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.