From 78d274099aafc3071550dbac2f15e3371b50d6d1 Mon Sep 17 00:00:00 2001
From: antpb <antpb@git.wordpress.org>
Date: Sun, 7 Nov 2021 20:37:58 +0000
Subject: [PATCH] Media: Add filter for post thumbnail id.

Introduces new filter `post_thumbnail_id` which allows overriding the default id returned from `get_post_thumbnail_id()`.

Props engelen, alexvorn2, gilbitron, sebastianpisula, SergeyBiryukov, leogermani, rzen, joemcgill, audrasjb.
Fixes #23983.


Built from https://develop.svn.wordpress.org/trunk@52028


git-svn-id: http://core.svn.wordpress.org/trunk@51620 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/post-thumbnail-template.php | 12 +++++++++++-
 wp-includes/version.php                 |  2 +-
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/wp-includes/post-thumbnail-template.php b/wp-includes/post-thumbnail-template.php
index 6c8fa584a1..79b9a55d3a 100644
--- a/wp-includes/post-thumbnail-template.php
+++ b/wp-includes/post-thumbnail-template.php
@@ -57,7 +57,17 @@ function get_post_thumbnail_id( $post = null ) {
 		return false;
 	}
 
-	return (int) get_post_meta( $post->ID, '_thumbnail_id', true );
+	$thumbnail_id = (int) get_post_meta( $post->ID, '_thumbnail_id', true );
+
+	/**
+	 * Filters post thumbnail ID.
+	 *
+	 * @since 5.9.0
+	 *
+	 * @param int|false        $thumbnail_id Post thumbnail ID or false if the post does not exist.
+	 * @param int|WP_Post|null $post         Post ID or WP_Post object. Default is global `$post`.
+	 */
+	return (int) apply_filters( 'post_thumbnail_id', $thumbnail_id, $post );
 }
 
 /**
diff --git a/wp-includes/version.php b/wp-includes/version.php
index b9423ad53a..a2a5857dd3 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.9-alpha-52027';
+$wp_version = '5.9-alpha-52028';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.