From 7a8beaca669df378b6acfeb74cdecd3c54a06258 Mon Sep 17 00:00:00 2001
From: Sipke Schoorstra <sipkeschoorstra@outlook.com>
Date: Mon, 28 Nov 2022 21:42:40 +0100
Subject: [PATCH] Fix stack overflow for looping constructs

---
 .../Elsa.Workflows.Core/Implementations/ActivityWalker.cs     | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/modules/Elsa.Workflows.Core/Implementations/ActivityWalker.cs b/src/modules/Elsa.Workflows.Core/Implementations/ActivityWalker.cs
index 97771effe..e100acc24 100644
--- a/src/modules/Elsa.Workflows.Core/Implementations/ActivityWalker.cs
+++ b/src/modules/Elsa.Workflows.Core/Implementations/ActivityWalker.cs
@@ -37,6 +37,10 @@ public class ActivityWalker : IActivityWalker
 
         foreach (var port in ports)
         {
+            // Continue if the specified activity was already encountered.
+            if (collectedActivities.Contains(port))
+                continue;
+            
             var childNode = collectedNodes.FirstOrDefault(x => x.Activity == port);
 
             if (childNode == null)