From e37882011f90fae035f20e214bf3b24b0868cf9a Mon Sep 17 00:00:00 2001
From: Hypolite Petovan <hypolite@mrpetovan.com>
Date: Sun, 29 Jan 2023 10:30:56 -0500
Subject: [PATCH] Add support for local files for unsecured document loading

- $http_response_header isn't set in the local file read case
---
 jsonld.php | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/jsonld.php b/jsonld.php
index 28361af..34b3df3 100644
--- a/jsonld.php
+++ b/jsonld.php
@@ -346,7 +346,7 @@ function jsonld_get_url($url)
 /**
  * The default implementation to retrieve JSON-LD at the given URL.
  *
- * @param string $url the URL to to retrieve.
+ * @param string $url The document URL or a local path
  *
  * @return stdClass the RemoteDocument object.
  */
@@ -388,7 +388,7 @@ function jsonld_default_document_loader($url)
 	}
 
 	$link_header = [];
-	foreach ($http_response_header as $header) {
+	foreach ($http_response_header ?? [] as $header) {
 		if (strpos($header, 'link') === 0) {
 			$value = explode(': ', $header);
 			if (count($value) > 1) {