From 12e33a06124a283c58012476fa32380f77884e52 Mon Sep 17 00:00:00 2001
From: implecao <yuyuyu4993@qq.com>
Date: Mon, 12 Jul 2021 00:07:13 +0800
Subject: [PATCH] 2021-07-11 night commit
MIME-Version: 1.0
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1. Bugfix：When calling canvas.toDataURL after initCenteringGuidelines(canvas) or initAligningGuidelines(canvas) it will cause a “Reference clearRect of null” error.
---
 lib/aligning_guidelines.js  | 4 +++-
 lib/centering_guidelines.js | 4 +++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/lib/aligning_guidelines.js b/lib/aligning_guidelines.js
index 68c6b3f831f..188282fbb3e 100644
--- a/lib/aligning_guidelines.js
+++ b/lib/aligning_guidelines.js
@@ -190,7 +190,9 @@ function initAligningGuidelines(canvas) {
   });
 
   canvas.on('before:render', function() {
-    canvas.clearContext(canvas.contextTop);
+    if (canvas.contextTop) {
+      canvas.clearContext(canvas.contextTop);
+    }
   });
 
   canvas.on('after:render', function() {
diff --git a/lib/centering_guidelines.js b/lib/centering_guidelines.js
index 5c6f6c8ed7e..761e781a4b4 100644
--- a/lib/centering_guidelines.js
+++ b/lib/centering_guidelines.js
@@ -68,7 +68,9 @@ function initCenteringGuidelines(canvas) {
   });
 
   canvas.on('before:render', function() {
-    canvas.clearContext(canvas.contextTop);
+    if (canvas.contextTop) {
+      canvas.clearContext(canvas.contextTop);
+    }
   });
 
   canvas.on('after:render', function() {