From 6fa2ee7f4a40de6a6faed2227b39533b0ff79803 Mon Sep 17 00:00:00 2001
From: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>
Date: Mon, 14 Nov 2022 10:15:26 +0100
Subject: Fix crash when resetting a QShader

shader = QShader() would crash because qAtomicAssign() requires that
the other's d-pointer is non-null. Follows pattern from other usages
in Qt.

Pick-to: 6.2 6.4
Fixes: QTBUG-108121
Change-Id: I57d25a804340839d03f9dadcbd44e956fb259c30
Reviewed-by: Paul Wicking <paul.wicking@qt.io>
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>
---
 src/gui/rhi/qshader.cpp | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

(limited to 'src/gui/rhi')

diff --git a/src/gui/rhi/qshader.cpp b/src/gui/rhi/qshader.cpp
index 85a0271272..e27ac8365e 100644
--- a/src/gui/rhi/qshader.cpp
+++ b/src/gui/rhi/qshader.cpp
@@ -241,7 +241,13 @@ QShader::QShader(const QShader &other)
 QShader &QShader::operator=(const QShader &other)
 {
     if (d) {
-        qAtomicAssign(d, other.d);
+        if (other.d) {
+            qAtomicAssign(d, other.d);
+        } else {
+            if (!d->ref.deref())
+                delete d;
+            d = nullptr;
+        }
     } else if (other.d) {
         other.d->ref.ref();
         d = other.d;
-- 
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