From f06762d1e8bb22565b8f15e5d72a27964977e3ae Mon Sep 17 00:00:00 2001
From: Anton Afanasyeu <a.afanasieff@gmail.com>
Date: Tue, 23 Jun 2026 18:53:34 +0200
Subject: [PATCH] url-shortener: QR encodes short URL with src=qr; forward
 query on redirect

QrHandler uses shortUrlForQr; RedirectHandler merges query string onto origin.

Co-authored-by: Cursor <cursoragent@cursor.com>
---
 src/LinkRepository.php  | 6 ++++++
 src/QrHandler.php       | 2 +-
 src/RedirectHandler.php | 8 +++++++-
 3 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/src/LinkRepository.php b/src/LinkRepository.php
index 9507507..3892485 100644
--- a/src/LinkRepository.php
+++ b/src/LinkRepository.php
@@ -10,6 +10,12 @@ final class LinkRepository {
         return self::publicBase() . '/' . $slug;
     }
 
+    /** URL encoded in QR PNGs — always tagged for analytics. */
+    public static function shortUrlForQr(string $slug): string {
+        $url = self::shortUrl($slug);
+        return str_contains($url, '?') ? $url . '&src=qr' : $url . '?src=qr';
+    }
+
     /** @return array<string,mixed>|null */
     public static function findActiveByBearerOrigin(int $bearerId, string $originHash): ?array {
         $pdo = Database::pdo();
diff --git a/src/QrHandler.php b/src/QrHandler.php
index cf59f46..62c057c 100644
--- a/src/QrHandler.php
+++ b/src/QrHandler.php
@@ -18,7 +18,7 @@ final class QrHandler {
         }
 
         $size = max(128, min(512, $size));
-        $target = LinkRepository::shortUrl($slug);
+        $target = LinkRepository::shortUrlForQr($slug);
         $png = self::renderPng($target, $size);
         if ($png === null) {
             JsonResponse::error(503, 'INTERNAL', 'QR generation unavailable (install qrencode on BE)');
diff --git a/src/RedirectHandler.php b/src/RedirectHandler.php
index 0ce9163..32ce54b 100644
--- a/src/RedirectHandler.php
+++ b/src/RedirectHandler.php
@@ -12,8 +12,14 @@ final class RedirectHandler {
         }
         LinkRepository::recordRedirect($slug);
         AuditLog::write('redirect', (int) $link['bearer_id'], $slug, '');
+        $dest = (string) $link['origin'];
+        $query = (string) ($_SERVER['QUERY_STRING'] ?? '');
+        if ($query !== '') {
+            $dest .= str_contains($dest, '?') ? '&' : '?';
+            $dest .= $query;
+        }
         http_response_code(302);
-        header('Location: ' . (string) $link['origin']);
+        header('Location: ' . $dest);
         exit;
     }