WebPage: Workaround changing webchannel world not sometimes working

Closes #2577

src/lib/webengine/webpage.cpp

@@ -73,8 +73,6 @@ WebPage::WebPage(QObject* parent)
     , m_blockAlerts(false)
     , m_secureStatus(false)
 {
-    setupWebChannelForUrl(QUrl());
-
     connect(this, &QWebEnginePage::loadProgress, this, &WebPage::progress);
     connect(this, &QWebEnginePage::loadFinished, this, &WebPage::finished);
     connect(this, &QWebEnginePage::urlChanged, this, &WebPage::urlChanged);
@@ -109,6 +107,14 @@ WebPage::WebPage(QObject* parent)
             }
         });
     }
+
+    // Workaround for changing webchannel world inside acceptNavigationRequest not working
+    m_setupChannelTimer = new QTimer(this);
+    m_setupChannelTimer->setSingleShot(true);
+    m_setupChannelTimer->setInterval(100);
+    connect(m_setupChannelTimer, &QTimer::timeout, this, [this]() {
+        setupWebChannelForUrl(m_channelUrl);
+    });
 }
 
 WebPage::~WebPage()
@@ -377,10 +383,15 @@ void WebPage::setupWebChannelForUrl(const QUrl &url)
         channel = new QWebChannel(this);
         ExternalJsObject::setupWebChannel(channel, this);
     }
+    int worldId = -1;
     if (url.scheme() == QL1S("falkon") || url.scheme() == QL1S("extension")) {
-        setWebChannel(channel, UnsafeJsWorld);
+        worldId = UnsafeJsWorld;
     } else {
-        setWebChannel(channel, SafeJsWorld);
+        worldId = SafeJsWorld;
+    }
+    if (worldId != m_channelWorldId) {
+        m_channelWorldId = worldId;
+        setWebChannel(channel, m_channelWorldId);
     }
 }
 
@@ -407,8 +418,8 @@ bool WebPage::acceptNavigationRequest(const QUrl &url, QWebEnginePage::Navigatio
             const bool isWeb = url.scheme() == QL1S("http") || url.scheme() == QL1S("https") || url.scheme() == QL1S("file");
             const bool globalJsEnabled = mApp->webSettings()->testAttribute(QWebEngineSettings::JavascriptEnabled);
             settings()->setAttribute(QWebEngineSettings::JavascriptEnabled, isWeb ? globalJsEnabled : true);
-
-            setupWebChannelForUrl(url);
+            m_channelUrl = url;
+            m_setupChannelTimer->start();
         }
         emit navigationRequestAccepted(url, type, isMainFrame);
     }

src/lib/webengine/webpage.h

@@ -109,6 +109,10 @@ private:
 
     QMetaObject::Connection m_contentsResizedConnection;
 
+    QUrl m_channelUrl;
+    int m_channelWorldId = -1;
+    QTimer *m_setupChannelTimer = nullptr;
+
     friend class WebView;
 };