From e69436a27d23cd70846e23d1d5d3370b18e34476 Mon Sep 17 00:00:00 2001
From: itsmattkc <34096995+itsmattkc@users.noreply.github.com>
Date: Sun, 19 Jun 2022 09:35:28 -0700
Subject: [PATCH] viewer: null check shaders before destroy

---
 app/widget/viewer/viewerdisplay.cpp | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/app/widget/viewer/viewerdisplay.cpp b/app/widget/viewer/viewerdisplay.cpp
index 7d6d660c9..1d03c75fb 100644
--- a/app/widget/viewer/viewerdisplay.cpp
+++ b/app/widget/viewer/viewerdisplay.cpp
@@ -503,10 +503,14 @@ void ViewerDisplayWidget::OnPaint()
 
 void ViewerDisplayWidget::OnDestroy()
 {
-  renderer()->DestroyNativeShader(deinterlace_shader_);
-  deinterlace_shader_.clear();
-  renderer()->DestroyNativeShader(blank_shader_);
-  blank_shader_.clear();
+  if (!deinterlace_shader_.isNull()) {
+    renderer()->DestroyNativeShader(deinterlace_shader_);
+    deinterlace_shader_.clear();
+  }
+  if (!blank_shader_.isNull()) {
+    renderer()->DestroyNativeShader(blank_shader_);
+    blank_shader_.clear();
+  }
 
   super::OnDestroy();