From 2807cf2f7ab7bdc092e81b3ed26b17174ff35d3d Mon Sep 17 00:00:00 2001
From: Andreas Weswaldi <37552851+weswaldix@users.noreply.github.com>
Date: Mon, 9 Sep 2024 14:22:32 +0200
Subject: [PATCH 1/2] Fix: Validate Austrian postal codes to exclude invalid
 values starting with 0

Previously, postal codes such as '0000' or '0999' were considered valid, but in reality, Austrian postal codes always start with digits from 1 to 9. This update corrects the validation to ensure compliance with the Austrian postal code system (see: https://en.wikipedia.org/wiki/Postal_codes_in_Austria#System).
---
 src/Formatter/ATFormatter.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Formatter/ATFormatter.php b/src/Formatter/ATFormatter.php
index d010f47..bb714cd 100644
--- a/src/Formatter/ATFormatter.php
+++ b/src/Formatter/ATFormatter.php
@@ -21,7 +21,7 @@ class ATFormatter implements CountryPostcodeFormatter
      */
     public function format(string $postcode) : ?string
     {
-        if (preg_match('/^[0-9]{4}$/', $postcode) !== 1) {
+        if (preg_match('/^[1-9][0-9]{3}$/', $postcode) !== 1) {
             return null;
         }
 

From fe22bfb7a2fd7c8b3c0740be8695300422e63d05 Mon Sep 17 00:00:00 2001
From: Andreas Weswaldi <37552851+weswaldix@users.noreply.github.com>
Date: Mon, 16 Sep 2024 09:40:46 +0200
Subject: [PATCH 2/2] Fix: Validate Austrian post codes to exclude invalid
 values starting with 0

Updated docblock
---
 src/Formatter/ATFormatter.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Formatter/ATFormatter.php b/src/Formatter/ATFormatter.php
index bb714cd..80c199a 100644
--- a/src/Formatter/ATFormatter.php
+++ b/src/Formatter/ATFormatter.php
@@ -9,7 +9,7 @@
 /**
  * Validates and formats postcodes in Austria.
  *
- * Postcodes consist of 4 digits, without separator.
+ * Postcodes consist of 4 digits, without separator. The first digit must be 1-9.
  *
  * @see https://en.wikipedia.org/wiki/List_of_postal_codes
  * @see https://en.wikipedia.org/wiki/Postal_codes_in_Austria