Fix crash on exit with url-request interceptors

If the interceptor is the child of the profile, they will be deleted
with the API profile which is before the underlying browser-context,
they should therefore be unset from the browser context first.

Task-number: QTBUG-60236
Change-Id: I2954e8106863b8b421ef166f6bf8fa79240c95ee
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>

src/core/browser_context_adapter.cpp

@@ -162,6 +162,8 @@ QWebEngineUrlRequestInterceptor *BrowserContextAdapter::requestInterceptor()
 
 void BrowserContextAdapter::setRequestInterceptor(QWebEngineUrlRequestInterceptor *interceptor)
 {
+    if (m_requestInterceptor == interceptor)
+        return;
     m_requestInterceptor = interceptor;
     if (m_browserContext->url_request_getter_.get())
         m_browserContext->url_request_getter_->updateRequestInterceptor();

src/webengine/api/qquickwebengineprofile.cpp

@@ -153,6 +153,8 @@ QQuickWebEngineProfilePrivate::QQuickWebEngineProfilePrivate(QSharedPointer<Brow
 
 QQuickWebEngineProfilePrivate::~QQuickWebEngineProfilePrivate()
 {
+    m_browserContextRef->setRequestInterceptor(nullptr);
+
     m_browserContextRef->removeClient(this);
 
     Q_FOREACH (QQuickWebEngineDownloadItem* download, m_ongoingDownloads) {

src/webenginewidgets/api/qwebengineprofile.cpp

@@ -156,6 +156,10 @@ QWebEngineProfilePrivate::QWebEngineProfilePrivate(QSharedPointer<BrowserContext
 
 QWebEngineProfilePrivate::~QWebEngineProfilePrivate()
 {
+    // In the case the user sets this profile as the parent of the interceptor
+    // it can be deleted before the browser-context still referencing it is.
+    m_browserContextRef->setRequestInterceptor(nullptr);
+
     delete m_settings;
     m_settings = 0;
     m_browserContextRef->removeClient(this);