From b8cdf1be50ab8d6cfb7b3e594bc8558f64376acf Mon Sep 17 00:00:00 2001
From: Timothy Jacobs <timothyblynjacobs@git.wordpress.org>
Date: Sat, 24 Oct 2020 13:18:50 +0000
Subject: [PATCH] REST API: Support generating comment up links to custom posts
 controllers.

The comments controller now uses the `rest_get_route_for_post` function introduced in WordPress 5.5 to generate the link. This function is filterable to allow for custom controllers to properly define their REST API route.

Props dsifford, TimothyBlynJacobs.
Fixes #44152.


git-svn-id: https://develop.svn.wordpress.org/trunk@49299 602fd350-edb4-49c9-b593-d223f7449a82
---
 .../endpoints/class-wp-rest-comments-controller.php    | 10 ++++------
 .../tests/rest-api/rest-comments-controller.php        |  4 ++++
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-comments-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-comments-controller.php
index b921144684..85c8f22e8b 100644
--- a/src/wp-includes/rest-api/endpoints/class-wp-rest-comments-controller.php
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-comments-controller.php
@@ -1159,14 +1159,12 @@ class WP_REST_Comments_Controller extends WP_REST_Controller {
 		}
 
 		if ( 0 !== (int) $comment->comment_post_ID ) {
-			$post = get_post( $comment->comment_post_ID );
-
-			if ( ! empty( $post->ID ) ) {
-				$obj  = get_post_type_object( $post->post_type );
-				$base = ! empty( $obj->rest_base ) ? $obj->rest_base : $obj->name;
+			$post       = get_post( $comment->comment_post_ID );
+			$post_route = rest_get_route_for_post( $post );
 
+			if ( ! empty( $post->ID ) && $post_route ) {
 				$links['up'] = array(
-					'href'       => rest_url( 'wp/v2/' . $base . '/' . $comment->comment_post_ID ),
+					'href'       => rest_url( $post_route ),
 					'embeddable' => true,
 					'post_type'  => $post->post_type,
 				);
diff --git a/tests/phpunit/tests/rest-api/rest-comments-controller.php b/tests/phpunit/tests/rest-api/rest-comments-controller.php
index ba67234a23..f61f438b05 100644
--- a/tests/phpunit/tests/rest-api/rest-comments-controller.php
+++ b/tests/phpunit/tests/rest-api/rest-comments-controller.php
@@ -3254,6 +3254,10 @@ class WP_Test_REST_Comments_Controller extends WP_Test_REST_Controller_Testcase
 			array_keys( $links )
 		);
 
+		if ( $comment->comment_post_ID ) {
+			$this->assertEquals( rest_url( '/wp/v2/posts/' . $comment->comment_post_ID ), $links['up'][0]['href'] );
+		}
+
 		if ( 'edit' === $context ) {
 			$this->assertSame( $comment->comment_author_email, $data['author_email'] );
 			$this->assertSame( $comment->comment_author_IP, $data['author_ip'] );