From bca31c38467c56b88d0e390bca21b13bab9cb425 Mon Sep 17 00:00:00 2001
From: Iliya Katushenock <modormoder@gmail.com>
Date: Mon, 11 Mar 2024 19:17:27 +0100
Subject: [PATCH] Fix: handle cyclic links when detecting dangling reroutes

Fix of error from 95810eec8f50429824fcf218d5fffaf67bfbbe5f

Pull Request: https://projects.blender.org/blender/blender/pulls/119335
---
 source/blender/blenkernel/intern/node.cc | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/source/blender/blenkernel/intern/node.cc b/source/blender/blenkernel/intern/node.cc
index 6d722807fd9..fab68a2badc 100644
--- a/source/blender/blenkernel/intern/node.cc
+++ b/source/blender/blenkernel/intern/node.cc
@@ -2488,14 +2488,17 @@ bool nodeIsDanglingReroute(const bNodeTree *ntree, const bNode *node)
 {
   ntree->ensure_topology_cache();
   BLI_assert(node_tree_runtime::topology_cache_is_available(*ntree));
-  BLI_assert(!ntree->has_available_link_cycle());
 
   const bNode *iter_node = node;
-  if (!iter_node->is_reroute()) {
-    return false;
-  }
-
+  Set<const bNode *> visited_nodes;
   while (true) {
+    if (!iter_node->is_reroute()) {
+      return false;
+    }
+    if (!visited_nodes.add(iter_node)) {
+      /* Treat cycle of reroute as dangling reroute branch. */
+      return true;
+    }
     const Span<const bNodeLink *> links = iter_node->input_socket(0).directly_linked_links();
     BLI_assert(links.size() <= 1);
     if (links.is_empty()) {
@@ -2509,9 +2512,6 @@ bool nodeIsDanglingReroute(const bNodeTree *ntree, const bNode *node)
       return false;
     }
     iter_node = link.fromnode;
-    if (!iter_node->is_reroute()) {
-      return false;
-    }
   }
 }