From cd1686e55f706048286cbc962bbe02032c2396cd Mon Sep 17 00:00:00 2001
From: David Redondo <qt@david-redondo.de>
Date: Wed, 15 Jan 2025 13:52:13 +0100
Subject: [PATCH] QOpenGlContext: Always unset current context in doneCurrent()

Otherwise when no other context is made current until thread exit, the
QGuiGLThreadContext destructor will try to call doneCurrent() on an
already deleted context.

Pick-to: 6.9 6.8
Change-Id: If55dd69a72b8ab4012780a449f6a02729dd0ed43
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>
---
 src/gui/kernel/qopenglcontext.cpp      | 10 ++++-----
 tests/auto/gui/qopengl/tst_qopengl.cpp | 28 ++++++++++++++++++++++++++
 2 files changed, 33 insertions(+), 5 deletions(-)

diff --git a/src/gui/kernel/qopenglcontext.cpp b/src/gui/kernel/qopenglcontext.cpp
index dd41318f72a..c25132dc734 100644
--- a/src/gui/kernel/qopenglcontext.cpp
+++ b/src/gui/kernel/qopenglcontext.cpp
@@ -743,13 +743,13 @@ bool QOpenGLContext::makeCurrent(QSurface *surface)
 void QOpenGLContext::doneCurrent()
 {
     Q_D(QOpenGLContext);
-    if (!isValid())
-        return;
 
-    if (QOpenGLContext::currentContext() == this)
-        d->shareGroup->d_func()->deletePendingResources(this);
+    if (isValid()) {
+        if (QOpenGLContext::currentContext() == this)
+            d->shareGroup->d_func()->deletePendingResources(this);
+        d->platformGLContext->doneCurrent();
+    }
 
-    d->platformGLContext->doneCurrent();
     QOpenGLContextPrivate::setCurrentContext(nullptr);
 
     d->surface = nullptr;
diff --git a/tests/auto/gui/qopengl/tst_qopengl.cpp b/tests/auto/gui/qopengl/tst_qopengl.cpp
index af59f3e31a3..3f4aa8cd8f9 100644
--- a/tests/auto/gui/qopengl/tst_qopengl.cpp
+++ b/tests/auto/gui/qopengl/tst_qopengl.cpp
@@ -84,6 +84,9 @@ private slots:
     void bufferCreate();
     void bufferMapRange();
     void defaultQGLCurrentBuffer();
+#if QT_CONFIG(egl)
+    void dontCrashOnInvalidContextThreadTeardown();
+#endif
 };
 
 struct SharedResourceTracker
@@ -1751,6 +1754,31 @@ void tst_QOpenGL::clipRect()
     //QCOMPARE(fb.pixelColor(clipRect.right(), clipRect.top() + 1), QColor(Qt::red));
 }
 
+#if QT_CONFIG(egl)
+void tst_QOpenGL::dontCrashOnInvalidContextThreadTeardown()
+{
+    class Thread : public QThread
+    {
+        void run() override
+        {
+            auto context = std::make_unique<QOpenGLContext>();
+            QVERIFY(context->create());
+            QScopedPointer<QSurface> surface(createSurface(int(QSurface::Window)));
+            QVERIFY(context->makeCurrent(surface.data()));
+            auto eglContext = context->nativeInterface<QNativeInterface::QEGLContext>();
+            if (!eglContext) {
+                QSKIP("Need an egl context for this test");
+            }
+            eglContext->invalidateContext();
+            context->doneCurrent();
+        }
+    };
+    Thread thread;
+    thread.start();
+    thread.wait();
+}
+#endif
+
 QTEST_MAIN(tst_QOpenGL)
 
 #include "tst_qopengl.moc"