From ee81e1acf48bfb80ffaba6ab657da6154252ce81 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tor=20Arne=20Vestb=C3=B8?= <tor.arne.vestbo@qt.io>
Date: Fri, 26 Aug 2022 10:57:42 +0200
Subject: [PATCH] Simplify QNetworkListManagerNetworkInformationBackend's COM
 handling
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The class used to be implicitly movable to a different thread, but this
is no longer the case, so we don't need to initialize and uninitialize
the COM library in start() and stop(). A qFatal has been added to ensure
we detect if this will be required again.

Change-Id: Ib22fe0bdcd5cb96f05632b09803c5de8ff43279a
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
---
 ...rklistmanagernetworkinformationbackend.cpp | 23 +++++--------------
 1 file changed, 6 insertions(+), 17 deletions(-)

diff --git a/src/plugins/networkinformation/networklistmanager/qnetworklistmanagernetworkinformationbackend.cpp b/src/plugins/networkinformation/networklistmanager/qnetworklistmanagernetworkinformationbackend.cpp
index d5582ebb30c..6862077abaf 100644
--- a/src/plugins/networkinformation/networklistmanager/qnetworklistmanagernetworkinformationbackend.cpp
+++ b/src/plugins/networkinformation/networklistmanager/qnetworklistmanagernetworkinformationbackend.cpp
@@ -143,6 +143,7 @@ QNetworkListManagerNetworkInformationBackend::~QNetworkListManagerNetworkInforma
     if (comInitFailed)
         return;
     stop();
+    CoUninitialize();
 }
 
 void QNetworkListManagerNetworkInformationBackend::setConnectivity(NLM_CONNECTIVITY newConnectivity)
@@ -164,11 +165,8 @@ void QNetworkListManagerNetworkInformationBackend::checkCaptivePortal()
 
 bool QNetworkListManagerNetworkInformationBackend::event(QEvent *event)
 {
-    if (event->type() == QEvent::ThreadChange && monitoring) {
-        stop();
-        QMetaObject::invokeMethod(this, &QNetworkListManagerNetworkInformationBackend::start,
-                                  Qt::QueuedConnection);
-    }
+    if (event->type() == QEvent::ThreadChange)
+        qFatal("Moving QNetworkListManagerNetworkInformationBackend to different thread is not supported");
 
     return QObject::event(event);
 }
@@ -177,15 +175,9 @@ bool QNetworkListManagerNetworkInformationBackend::start()
 {
     Q_ASSERT(!monitoring);
 
-    if (comInitFailed) {
-        auto hr = CoInitializeEx(nullptr, COINIT_APARTMENTTHREADED | COINIT_DISABLE_OLE1DDE);
-        if (FAILED(hr)) {
-            qCWarning(lcNetInfoNLM) << "Failed to initialize COM:" << errorStringFromHResult(hr);
-            comInitFailed = true;
-            return false;
-        }
-        comInitFailed = false;
-    }
+    if (comInitFailed)
+        return false;
+
     if (!managerEvents)
         managerEvents = new QNetworkListManagerEvents();
 
@@ -203,9 +195,6 @@ void QNetworkListManagerNetworkInformationBackend::stop()
         monitoring = false;
         managerEvents.Reset();
     }
-
-    CoUninitialize();
-    comInitFailed = true; // we check this value in start() to see if we need to re-initialize
 }
 
 QT_END_NAMESPACE