From 36d25343f4c0ad0b8c2d01b684689073f35a302a Mon Sep 17 00:00:00 2001
From: Neil Fraser <fraser@google.com>
Date: Tue, 15 Jun 2021 23:07:50 -0700
Subject: [PATCH] =?UTF-8?q?Don=E2=80=99t=20hide=20insertion=20marker=20if?=
 =?UTF-8?q?=20it=E2=80=99s=20already=20gone?=
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Fixes #2338.

I also looked at having workspace.clear delete any insertion marker, but there doesn’t appear to be a public API for this.  Shouldn’t matter, this should be sufficient.
---
 core/insertion_marker_manager.js | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/core/insertion_marker_manager.js b/core/insertion_marker_manager.js
index 2077333e4..0e038d666 100644
--- a/core/insertion_marker_manager.js
+++ b/core/insertion_marker_manager.js
@@ -674,7 +674,10 @@ Blockly.InsertionMarkerManager.prototype.hideInsertionMarker_ = function() {
   }
 
   this.markerConnection_ = null;
-  imBlock.getSvgRoot().setAttribute('visibility', 'hidden');
+  var svg = imBlock.getSvgRoot();
+  if (svg) {
+    svg.setAttribute('visibility', 'hidden');
+  }
 };
 
 /**