Hide button for file upload only if server actively disables it

src/UploadManager.cpp

@@ -50,11 +50,10 @@ UploadManager::UploadManager(QXmppClient *client, RosterManager* rosterManager,
 {
 	client->addExtension(&m_manager);
 
+	connect(&m_manager, &QXmppUploadManager::serviceFoundChanged, this, &UploadManager::handleHttpFileUploadSupportedChanged);
+
 	connect(Kaidan::instance(), &Kaidan::sendFile, this, &UploadManager::sendFile);
 
-	connect(&m_manager, &QXmppUploadManager::serviceFoundChanged, this, [=]() {
-		Kaidan::instance()->serverFeaturesCache()->setHttpUploadSupported(m_manager.serviceFound());
-	});
 	connect(&m_manager, &QXmppUploadManager::uploadSucceeded,
 	        this, &UploadManager::handleUploadSucceeded);
 	connect(&m_manager, &QXmppUploadManager::uploadFailed,
@@ -142,6 +141,13 @@ void UploadManager::handleUploadSucceeded(const QXmppHttpUpload *upload)
 	emit Kaidan::instance()->transferCache()->removeJobRequested(originalMsg->id());
 }
 
+void UploadManager::handleHttpFileUploadSupportedChanged()
+{
+	if (m_client->isConnected()) {
+		Kaidan::instance()->serverFeaturesCache()->setHttpUploadSupported(m_manager.serviceFound());
+	}
+}
+
 void UploadManager::handleUploadFailed(const QXmppHttpUpload *upload)
 {
 	qDebug() << "[client] [UploadManager] A file upload has failed.";

src/UploadManager.h

@@ -68,6 +68,15 @@ public slots:
 	void handleUploadFailed(const QXmppHttpUpload *upload);
 	void handleUploadSucceeded(const QXmppHttpUpload *upload);
 
+private slots:
+	/**
+	 * Called when the HTTP File Upload support changed.
+	 *
+	 * The server feature state for HTTP File Upload is only changed when the server disables it, not on disconnect.
+	 * That way, the last known state can be cached while being offline and queuing a file for being sent as soon as Kaidan is online again can be offered to the user even if Kaidan is not connected to the user's server.
+	 */
+	void handleHttpFileUploadSupportedChanged();
+
 private:
 	QXmppClient *m_client;
 	QXmppUploadManager m_manager;