From 8a0c302142ee8b3aeaca298e1233fc8d77187136 Mon Sep 17 00:00:00 2001
From: Jeroen Stolp <jeroen.stolp@flexkids.nl>
Date: Mon, 6 Jan 2020 11:55:28 +0100
Subject: [PATCH] Adding Content-Length: 0 Head on PUT start transaction call

---
 src/SignhostClient.php | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/SignhostClient.php b/src/SignhostClient.php
index 36423b4..95f52ed 100644
--- a/src/SignhostClient.php
+++ b/src/SignhostClient.php
@@ -90,7 +90,12 @@ public function performRequest(string $endpoint, string $method, $data = null, $
             if ("GET" === $method || "HEAD" === $method && !isset($filePath)) {
                 unset($headers[0]); // unset Content-Type
             }
-            
+
+            // for start transaction, SignHost will require the content-lenth: 0 header.
+            if (false !== strpos($endpoint, 'start')) {
+                $headers[] = "Content-Length: 0";
+            }
+
             // Initialize a cURL session
             return $this->performCURLRequest(
                 $method,