From 9d235ff10a70a2de8ee12378618fda9397a87456 Mon Sep 17 00:00:00 2001
From: Philip Sargent <philip.sargent@gmail.com>
Date: Sat, 2 Aug 2025 15:31:41 +0200
Subject: [PATCH] prevent crash on broken QM parsing

---
 core/models/logbooks.py | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/core/models/logbooks.py b/core/models/logbooks.py
index fd6bbfe..4ea740d 100644
--- a/core/models/logbooks.py
+++ b/core/models/logbooks.py
@@ -271,12 +271,16 @@ class QM(TroggleModel):
 
     def get_absolute_url(self):
         # This reverse resolution stuff is pure magic. Just change the regex in urls.py and everything changes to suit. Whacky.
+        if self.cave:
+            id = self.cave.slug()
+        else:
+            id = None
         return urljoin(
             settings.URL_ROOT,
             reverse(
                 "qm",
                 kwargs={
-                    "cave_id": self.cave.slug(),
+                    "cave_id": id,
                     "year": self.expoyear,
                     "blockname": self.blockname,
                     "qm_id": self.number,