From 633eeccd81499ea3c807fa813e5fb93bb1876361 Mon Sep 17 00:00:00 2001
From: Yi-Ting Tu <ricktu256@gmail.com>
Date: Mon, 14 Oct 2024 16:19:45 -0400
Subject: [PATCH] Fix Ctrl+D error

---
 src/simulator/js/app.js | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/src/simulator/js/app.js b/src/simulator/js/app.js
index ef690e0e..68589ac0 100644
--- a/src/simulator/js/app.js
+++ b/src/simulator/js/app.js
@@ -374,14 +374,16 @@ async function startApp() {
     }
     //Ctrl+D
     if (e.ctrlKey && e.keyCode == 68) {
-      if (scene.objs[editor.selectedObjIndex].constructor.type == 'Handle') {
-        scene.cloneObjsByHandle(editor.selectedObjIndex);
-      } else {
-        scene.cloneObj(editor.selectedObjIndex);
-      }
+      if (editor.selectedObjIndex != -1) {
+        if (scene.objs[editor.selectedObjIndex].constructor.type == 'Handle') {
+          scene.cloneObjsByHandle(editor.selectedObjIndex);
+        } else {
+          scene.cloneObj(editor.selectedObjIndex);
+        }
 
-      simulator.updateSimulation(!scene.objs[editor.selectedObjIndex].constructor.isOptical, true);
-      editor.onActionComplete();
+        simulator.updateSimulation(!scene.objs[editor.selectedObjIndex].constructor.isOptical, true);
+        editor.onActionComplete();
+      }
       return false;
     }
     //Ctrl+Y