From 0173a138310a84f21d9042cd5073cb53f9cc023f Mon Sep 17 00:00:00 2001
From: Karoliine Holter <karoliine.holter@hotmail.com>
Date: Thu, 31 Oct 2024 21:52:05 +0200
Subject: [PATCH] When setting a breakpoint to the paper demo on line 21,
 stepping results in an "internal error"

---
 .../java/abstractdebugging/AbstractDebuggingServer.java   | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/main/java/abstractdebugging/AbstractDebuggingServer.java b/src/main/java/abstractdebugging/AbstractDebuggingServer.java
index ccc7afd..382a87f 100644
--- a/src/main/java/abstractdebugging/AbstractDebuggingServer.java
+++ b/src/main/java/abstractdebugging/AbstractDebuggingServer.java
@@ -811,9 +811,11 @@ private void stepAllThreadsIntoMatchingEdge(int primaryThreadId, EdgeInfo primar
         for (var step : steps) {
             ThreadState thread = step.getLeft();
             EdgeInfo targetEdge = step.getRight();
-            NodeInfo targetNode = resultsService.lookupNode(targetEdge.nodeId());
-            boolean isNewThread = targetEdge instanceof FunctionCallEdgeInfo fce && fce.createsNewThread();
-            thread.pushFrame(new StackFrameState(targetNode, false, thread.getCurrentFrame().getLocalThreadIndex() - (isNewThread ? 1 : 0)));
+            if (targetEdge != null) {
+                NodeInfo targetNode = resultsService.lookupNode(targetEdge.nodeId());
+                boolean isNewThread = targetEdge instanceof FunctionCallEdgeInfo fce && fce.createsNewThread();
+                thread.pushFrame(new StackFrameState(targetNode, false, thread.getCurrentFrame().getLocalThreadIndex() - (isNewThread ? 1 : 0)));
+            }
         }
 
         onThreadsStopped("step", primaryThreadId);