From 5149a7efd5a6e04ae369fdd14142147b29c22488 Mon Sep 17 00:00:00 2001
From: Timothy Jacobs <timothyblynjacobs@git.wordpress.org>
Date: Mon, 27 Jul 2020 18:44:14 +0000
Subject: [PATCH] REST API: Fix warning when using `set_param()` on a JSON
 request with no body.

In [47559] the `WP_REST_Request::set_param()` method was adjusted to try and overwrite an existing parameter definition before forcing the value in the first parameter slot. If `set_param()` was called on a request with an `application/json` content type and an empty body, a PHP warning would be issued. This was due to the JSON parameter type not being set to an array when the body is empty.

This commit avoids the warning by adding an `is_array()` check before calling `array_key_exists`. Ideally, `WP_REST_Reuest::parse_json_params()` would set the JSON parameter type to an empty array in this case, but that is too large of a change at this point in the cycle.

Props manooweb.
Fixes #50786.


git-svn-id: https://develop.svn.wordpress.org/trunk@48642 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-includes/rest-api/class-wp-rest-request.php |  4 ++--
 tests/phpunit/tests/rest-api/rest-request.php      | 14 ++++++++++++++
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/src/wp-includes/rest-api/class-wp-rest-request.php b/src/wp-includes/rest-api/class-wp-rest-request.php
index d9c24e0658..73548d4f38 100644
--- a/src/wp-includes/rest-api/class-wp-rest-request.php
+++ b/src/wp-includes/rest-api/class-wp-rest-request.php
@@ -408,7 +408,7 @@ class WP_REST_Request implements ArrayAccess {
 		$order = $this->get_parameter_order();
 
 		foreach ( $order as $type ) {
-			if ( array_key_exists( $key, $this->params[ $type ] ) ) {
+			if ( is_array( $this->params[ $type ] ) && array_key_exists( $key, $this->params[ $type ] ) ) {
 				return true;
 			}
 		}
@@ -433,7 +433,7 @@ class WP_REST_Request implements ArrayAccess {
 		$found_key = false;
 
 		foreach ( $order as $type ) {
-			if ( 'defaults' !== $type && array_key_exists( $key, $this->params[ $type ] ) ) {
+			if ( 'defaults' !== $type && is_array( $this->params[ $type ] ) && array_key_exists( $key, $this->params[ $type ] ) ) {
 				$this->params[ $type ][ $key ] = $value;
 				$found_key                     = true;
 			}
diff --git a/tests/phpunit/tests/rest-api/rest-request.php b/tests/phpunit/tests/rest-api/rest-request.php
index 9cbb0f3994..2a78db4660 100644
--- a/tests/phpunit/tests/rest-api/rest-request.php
+++ b/tests/phpunit/tests/rest-api/rest-request.php
@@ -765,4 +765,18 @@ class Tests_REST_Request extends WP_UnitTestCase {
 		$this->assertEquals( array( 'param' => 'new_value' ), $request->get_json_params() );
 		$this->assertEquals( array( 'param' => 'new_value' ), $request->get_query_params() );
 	}
+
+	/**
+	 * @ticket 50786
+	 */
+	public function test_set_param_with_invalid_json() {
+		$request = new WP_REST_Request();
+		$request->add_header( 'content-type', 'application/json' );
+		$request->set_method( 'POST' );
+		$request->set_body( '' );
+		$request->set_param( 'param', 'value' );
+
+		$this->assertTrue( $request->has_param( 'param' ) );
+		$this->assertEquals( 'value', $request->get_param( 'param' ) );
+	}
 }