Windows: Reset QNAM as a workaround. #2899 #2895 #2973

The QNetworkAccessManager is reset when we are disconnected, just
before attempting to fetch the server's status.php.

This may help fix the problem described in various issues where we
get 'Connection closed' or timeout errors after the OS has woken
from sleep.

src/gui/accountstate.cpp

@@ -179,6 +179,15 @@ void AccountState::checkConnectivity()
         conValidator->checkAuthentication();
     } else {
         // Check the server and then the auth.
+
+#ifdef Q_OS_WIN
+        // There seems to be a bug in Qt on Windows where QNAM sometimes stops
+        // working correctly after the computer woke up from sleep. See #2895 #2899
+        // and #2973.
+        // As an attempted workaround, reset the QNAM regularly if the account is
+        // disconnected.
+        account()->resetNetworkAccessManager();
+#endif
         conValidator->checkServerAndAuth();
     }
 }

src/libsync/account.cpp

@@ -271,6 +271,21 @@ void Account::clearCookieJar()
     _am->setCookieJar(new CookieJar);
 }
 
+void Account::resetNetworkAccessManager()
+{
+    if (!_credentials || !_am) {
+        return;
+    }
+
+    qDebug() << "Resetting QNAM";
+    QNetworkCookieJar* jar = _am->cookieJar();
+    _am->deleteLater();
+    _am = _credentials->getQNAM();
+    _am->setCookieJar(jar); // takes ownership of the old cookie jar
+    connect(_am, SIGNAL(sslErrors(QNetworkReply*,QList<QSslError>)),
+            SLOT(slotHandleErrors(QNetworkReply*,QList<QSslError>)));
+}
+
 QNetworkAccessManager *Account::networkAccessManager()
 {
     return _am;

src/libsync/account.h

@@ -156,6 +156,7 @@ public:
 
     void clearCookieJar();
 
+    void resetNetworkAccessManager();
     QNetworkAccessManager* networkAccessManager();
 
     /// Called by network jobs on credential errors.