From bc5e3eda243d60523cec782d090a56394ace2090 Mon Sep 17 00:00:00 2001
From: Stewart Allen <sa@grid.space>
Date: Thu, 16 Jun 2022 11:21:46 -0400
Subject: [PATCH] skip purge block when no prior points output

---
 src/kiri-mode/fdm/prepare.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/kiri-mode/fdm/prepare.js b/src/kiri-mode/fdm/prepare.js
index ec84479e..de81eaeb 100644
--- a/src/kiri-mode/fdm/prepare.js
+++ b/src/kiri-mode/fdm/prepare.js
@@ -625,7 +625,7 @@ FDM.prepare = function(widgets, settings, update) {
 
         // if a declared extruder isn't used in a layer, use selected
         // extruder to fill the relevant purge blocks for later support
-        track.slice().forEach(ext => {
+        if (lastOut) track.slice().forEach(ext => {
             printPoint = purge(ext.extruder, track, layerout, printPoint, lastOut.z, lastExt, lastOffset);
         });