Ticket #41738: 41738.diff

src/wp-includes/class-wp-customize-manager.php

@@ -816 +816 @@
                 if ( ! empty( $changeset_post_query->posts ) ) {
                         // Note: 'fields'=>'ids' is not being used in order to cache the post object as it will be needed.
                         $changeset_post_id = $changeset_post_query->posts[0]->ID;
-                        wp_cache_set( $this->_changeset_uuid, $changeset_post_id, $cache_group );
+                        wp_cache_set( $uuid, $changeset_post_id, $cache_group );
                         return $changeset_post_id;
                 }
 

tests/phpunit/tests/customize/manager.php

@@ -303 +303 @@
                 $wp_customize = new WP_Customize_Manager();
                 $this->assertNull( $wp_customize->find_changeset_post_id( wp_generate_uuid4() ) );
                 $this->assertEquals( $post_id, $wp_customize->find_changeset_post_id( $uuid ) );
+
+                // Verify that the found post ID was cached under the given UUID, not the manager's UUID.
+                $this->assertNotEquals( $post_id, $wp_customize->find_changeset_post_id( $wp_customize->changeset_uuid() ) );
         }
 
         /**