From e46c9d35ac3cd500b7c84bb81646ffb0887807d4 Mon Sep 17 00:00:00 2001
From: Jon Evans <jon@craftyjon.com>
Date: Mon, 5 Apr 2021 19:58:14 -0400
Subject: [PATCH] Add undo/redo handling to length tuner event loop

Fixes https://gitlab.com/kicad/code/kicad/-/issues/8129
---
 pcbnew/router/length_tuner_tool.cpp | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/pcbnew/router/length_tuner_tool.cpp b/pcbnew/router/length_tuner_tool.cpp
index b3f54feb9e..dd9707454f 100644
--- a/pcbnew/router/length_tuner_tool.cpp
+++ b/pcbnew/router/length_tuner_tool.cpp
@@ -292,6 +292,14 @@ int LENGTH_TUNER_TOOL::MainLoop( const TOOL_EVENT& aEvent )
         {
             break; // Finish
         }
+        else if( evt->Action() == TA_UNDO_REDO_PRE )
+        {
+            m_router->ClearWorld();
+        }
+        else if( evt->Action() == TA_UNDO_REDO_POST || evt->Action() == TA_MODEL_CHANGE )
+        {
+            m_router->SyncWorld();
+        }
         else if( evt->IsMotion() )
         {
             updateStartItem( *evt );