From 4f1592e5c1b417acafcd5292cdd1c2647e5b075a Mon Sep 17 00:00:00 2001
From: Seth Hillbrand <seth@kipro-pcb.com>
Date: Sat, 13 Feb 2021 06:41:10 -0800
Subject: [PATCH] Fix crash with empty undo stack

---
 eeschema/schematic_undo_redo.cpp | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/eeschema/schematic_undo_redo.cpp b/eeschema/schematic_undo_redo.cpp
index b7967eeadb..9dca9cfd45 100644
--- a/eeschema/schematic_undo_redo.cpp
+++ b/eeschema/schematic_undo_redo.cpp
@@ -117,10 +117,13 @@ void SCH_EDIT_FRAME::SaveCopyInUndoList( SCH_SCREEN*    aScreen,
 	PICKED_ITEMS_LIST* lastUndo = PopCommandFromUndoList();
 
 	// If the last stack was empty, use that one instead of creating a new stack
-    if( aAppend || !lastUndo->GetCount() )
-        commandToUndo = lastUndo;
-    else
-    	PushCommandToUndoList( lastUndo );
+	if( lastUndo )
+	{
+		if( aAppend || !lastUndo->GetCount() )
+			commandToUndo = lastUndo;
+		else
+			PushCommandToUndoList( lastUndo );
+	}
 
     if( !commandToUndo )
     {