From daf41ab17e245cfdc4064c4d69c89712ae7d126c Mon Sep 17 00:00:00 2001
From: jomo <jomo@aachen.ccc.de>
Date: Fri, 5 Aug 2022 02:08:51 +0200
Subject: [PATCH] detect indirect loops in tree

---
 static/index.js | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/static/index.js b/static/index.js
index 3e40dd6..c0fac55 100644
--- a/static/index.js
+++ b/static/index.js
@@ -39,18 +39,27 @@ function renderItems() {
 }
 
 function getLocString(items, item) {
-  if (item.is_in == item.id) {
-    return ['in ↻', `${item.id} is in itself`];
-  }
   let ancestors = [];
   let next = item;
+  let loop = false;
   while (next) {
+    if (ancestors.includes(next)) {
+      loop = true;
+      if (ancestors.length == 1) {
+        ancestors.push(null);
+      }
+      break;
+    }
     ancestors.unshift(next);
     next = items[next.is_in];
   }
   ancestors.pop();
-  const loc = ancestors.map(i => i.id).join(' ➜ ') || '⬚';
+  let loc = ancestors.map(i => i.id).join(' ➜ ') || '⬚';
   let longloc = ancestors.map(i => `${i.type || ''} ${i.id} ${i.name && `(${i.name})` || ''}`).join(' ➜ ') || 'universe';
+  if (loop) {
+    loc += ' ↻';
+    longloc += ' ↻';
+  }
   return [loc, `${item.id} is in ${longloc}`];
 }