From 1a0c2fb5bdaed175c9d9472b0658f93214572d4d Mon Sep 17 00:00:00 2001
From: Ulf Hermann <ulf.hermann@qt.io>
Date: Tue, 2 Jul 2019 13:21:41 +0200
Subject: When setting a QObject as context property reset it when it's
 destroyed

Fixes: QTBUG-76346
Change-Id: Ie21f831a775489f0f2ac2e296136ed4932f5154f
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>
---
 src/qml/qml/qqmlcontext.cpp | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

(limited to 'src/qml/qml/qqmlcontext.cpp')

diff --git a/src/qml/qml/qqmlcontext.cpp b/src/qml/qml/qqmlcontext.cpp
index bd59409475..14892bd6ad 100644
--- a/src/qml/qml/qqmlcontext.cpp
+++ b/src/qml/qml/qqmlcontext.cpp
@@ -317,6 +317,12 @@ void QQmlContext::setContextProperty(const QString &name, const QVariant &value)
         d->propertyValues[idx] = value;
         QMetaObject::activate(this, d->notifyIndex, idx, nullptr);
     }
+
+    if (auto *obj = qvariant_cast<QObject *>(value)) {
+        connect(obj, &QObject::destroyed, this, [d, name](QObject *destroyed) {
+            d->dropDestroyedQObject(name, destroyed);
+        });
+    }
 }
 
 /*!
@@ -524,6 +530,17 @@ QObject *QQmlContextPrivate::context_at(QQmlListProperty<QObject> *prop, int ind
     }
 }
 
+void QQmlContextPrivate::dropDestroyedQObject(const QString &name, QObject *destroyed)
+{
+    const int idx = data->propertyNames().value(name);
+    Q_ASSERT(idx >= 0);
+    if (qvariant_cast<QObject *>(propertyValues[idx]) != destroyed)
+        return;
+
+    propertyValues[idx] = QVariant::fromValue<QObject *>(nullptr);
+    QMetaObject::activate(q_func(), notifyIndex, idx, nullptr);
+}
+
 
 QQmlContextData::QQmlContextData()
     : QQmlContextData(nullptr)
-- 
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