From 3c762e1476e417dede1570f04e1f662deb1f50fa Mon Sep 17 00:00:00 2001
From: Stefan Hacker <duffy@debian-linux-terminal.local>
Date: Sun, 12 Apr 2026 13:53:24 +0200
Subject: [PATCH] fix: Well-Known DAV - OPTIONS liefert jetzt korrekt
 DAV-Header

Flask hat trotz expliziter OPTIONS-Route Auto-OPTIONS generiert,
wodurch der DAV-Header fehlte. DAVx5 sieht so keinen Calendar-
Access und lehnt den Server ab.

Konsolidiert zu einem Handler mit method-basiertem Dispatch und
provide_automatic_options=False, damit Flask nicht dazwischenfunkt.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 backend/app/__init__.py | 29 +++++++++++++++++------------
 1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/backend/app/__init__.py b/backend/app/__init__.py
index b85719d..20d1aeb 100644
--- a/backend/app/__init__.py
+++ b/backend/app/__init__.py
@@ -97,22 +97,27 @@ def create_app(config_class=Config):
     # Well-known URLs for CalDAV/CardDAV auto-discovery (iOS, DAVx5, etc.).
     # 301-Redirect bei PROPFIND ist bei einigen Clients zickig, deshalb
     # delegieren wir intern direkt an die DAV-Handler, statt zu redirecten.
+    from flask import request
     from app.dav.caldav import propfind as dav_propfind, options as dav_options
 
-    @app.route('/.well-known/caldav', methods=['GET', 'HEAD'])
-    @app.route('/.well-known/carddav', methods=['GET', 'HEAD'])
-    def wellknown_redirect():
+    def _wellknown_dav():
+        if request.method == 'PROPFIND':
+            return dav_propfind(subpath='')
+        if request.method == 'OPTIONS':
+            return dav_options()
         return redirect('/dav/', code=301)
 
-    @app.route('/.well-known/caldav', methods=['PROPFIND'])
-    @app.route('/.well-known/carddav', methods=['PROPFIND'])
-    def wellknown_propfind():
-        return dav_propfind(subpath='')
-
-    @app.route('/.well-known/caldav', methods=['OPTIONS'])
-    @app.route('/.well-known/carddav', methods=['OPTIONS'])
-    def wellknown_options():
-        return dav_options()
+    app.add_url_rule(
+        '/.well-known/caldav', view_func=_wellknown_dav,
+        methods=['GET', 'HEAD', 'PROPFIND', 'OPTIONS'],
+        provide_automatic_options=False,
+    )
+    app.add_url_rule(
+        '/.well-known/carddav', view_func=_wellknown_dav,
+        endpoint='_wellknown_carddav',
+        methods=['GET', 'HEAD', 'PROPFIND', 'OPTIONS'],
+        provide_automatic_options=False,
+    )
 
     # iCal export (public, no auth)
     @app.route('/ical/<token>')