From 5d25096cffdfbfd8a91c108f0894959f73628579 Mon Sep 17 00:00:00 2001
From: Zion Ng <zion@intzone.com>
Date: Wed, 10 Mar 2021 14:05:42 +0800
Subject: [PATCH] Ensure checksum is always 4 digits

---
 src/SgQr/Parser.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/SgQr/Parser.php b/src/SgQr/Parser.php
index ebdd1cd..53c2e5c 100644
--- a/src/SgQr/Parser.php
+++ b/src/SgQr/Parser.php
@@ -139,7 +139,7 @@ public function computeChecksum($text, $polynomialHex = 0x1021, $initialValue =
             }
         }
 
-        return strtoupper(dechex($result));
+        return str_pad(strtoupper(dechex($result)), 4, '0', STR_PAD_LEFT); // ensure 4 chars cos result may be shorter
     }
 
     /**