QNetworkReply: Propagate proxy errors properly

Map QNetworkError::HostNotFoundError and QNetworkError::ConnectionRefusedError
 to ProxyNotFoundError resp. ProxyConnectionRefusedError when it originated
from the communication with the proxy server.

Fixes: QTBUG-68821
Pick-to: 6.5 6.6
Change-Id: I21b91f2667ba0cd329d4ece1fe543472cdab2d22
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>

src/network/access/qhttpnetworkconnection.cpp

@@ -1265,8 +1265,16 @@ void QHttpNetworkConnectionPrivate::_q_hostLookupFinished(const QHostInfo &info)
         networkLayerState = QHttpNetworkConnectionPrivate::IPv6;
         QMetaObject::invokeMethod(this->q_func(), "_q_startNextRequest", Qt::QueuedConnection);
     } else {
+        auto lookupError = QNetworkReply::HostNotFoundError;
+#ifndef QT_NO_NETWORKPROXY
+        // if the proxy can lookup hostnames, all hostname lookups except for the lookup of the
+        // proxy hostname are delegated to the proxy.
+        auto proxyCapabilities = networkProxy.capabilities() | channels[0].proxy.capabilities();
+        if (proxyCapabilities & QNetworkProxy::HostNameLookupCapability)
+            lookupError = QNetworkReply::ProxyNotFoundError;
+#endif
         if (dequeueRequest(channels[0].socket)) {
-            emitReplyError(channels[0].socket, channels[0].reply, QNetworkReply::HostNotFoundError);
+            emitReplyError(channels[0].socket, channels[0].reply, lookupError);
             networkLayerState = QHttpNetworkConnectionPrivate::Unknown;
         } else if (connectionType == QHttpNetworkConnection::ConnectionTypeHTTP2
                    || connectionType == QHttpNetworkConnection::ConnectionTypeHTTP2Direct) {
@@ -1274,7 +1282,7 @@ void QHttpNetworkConnectionPrivate::_q_hostLookupFinished(const QHostInfo &info)
                 // emit error for all replies
                 QHttpNetworkReply *currentReply = h2Pair.second;
                 Q_ASSERT(currentReply);
-                emitReplyError(channels[0].socket, currentReply, QNetworkReply::HostNotFoundError);
+                emitReplyError(channels[0].socket, currentReply, lookupError);
             }
         } else {
             // We can end up here if a request has been aborted or otherwise failed (e.g. timeout)

src/network/access/qhttpnetworkconnectionchannel.cpp

@@ -949,6 +949,10 @@ void QHttpNetworkConnectionChannel::_q_error(QAbstractSocket::SocketError socket
         break;
     case QAbstractSocket::ConnectionRefusedError:
         errorCode = QNetworkReply::ConnectionRefusedError;
+#ifndef QT_NO_NETWORKPROXY
+        if (connection->d_func()->networkProxy.type() != QNetworkProxy::NoProxy && !ssl)
+            errorCode = QNetworkReply::ProxyConnectionRefusedError;
+#endif
         break;
     case QAbstractSocket::RemoteHostClosedError:
         // This error for SSL comes twice in a row, first from SSL layer ("The TLS/SSL connection has been closed") then from TCP layer.
@@ -1030,6 +1034,9 @@ void QHttpNetworkConnectionChannel::_q_error(QAbstractSocket::SocketError socket
         }
         errorCode = QNetworkReply::TimeoutError;
         break;
+    case QAbstractSocket::ProxyConnectionRefusedError:
+        errorCode = QNetworkReply::ProxyConnectionRefusedError;
+        break;
     case QAbstractSocket::ProxyAuthenticationRequiredError:
         errorCode = QNetworkReply::ProxyAuthenticationRequiredError;
         break;

tests/auto/network/access/qnetworkreply/tst_qnetworkreply.cpp

@@ -526,6 +526,9 @@ private Q_SLOTS:
     void notFoundWithCompression_data();
     void notFoundWithCompression();
 
+    void qtbug68821proxyError_data();
+    void qtbug68821proxyError();
+
     // NOTE: This test must be last!
     void parentingRepliesToTheApp();
 private:
@@ -3852,7 +3855,6 @@ void tst_QNetworkReply::ioGetFromHttpWithSocksProxy()
         QVERIFY(reader.data.isEmpty());
 
         QVERIFY(int(reply->error()) > 0);
-        QEXPECT_FAIL("", "QTcpSocket doesn't return enough information yet", Continue);
         QCOMPARE(int(reply->error()), int(QNetworkReply::ProxyConnectionRefusedError));
 
         QCOMPARE(authspy.size(), 0);
@@ -10094,6 +10096,48 @@ void tst_QNetworkReply::notFoundWithCompression()
     QCOMPARE(reply->readAll(), expected);
 }
 
+void tst_QNetworkReply::qtbug68821proxyError_data()
+{
+    QTest::addColumn<QString>("proxyHost");
+    QTest::addColumn<QString>("scheme");
+    QTest::addColumn<QNetworkReply::NetworkError>("error");
+
+    QTest::newRow("invalidhost+http") << "this-host-will-never-exist.qt-project.org"
+                                      << "http" << QNetworkReply::ProxyNotFoundError;
+    QTest::newRow("localhost+http") << "localhost"
+                                    << "http" << QNetworkReply::ProxyConnectionRefusedError;
+#ifndef QT_NO_SSL
+    QTest::newRow("invalidhost+https") << "this-host-will-never-exist.qt-project.org"
+                                       << "https" << QNetworkReply::ProxyNotFoundError;
+    QTest::newRow("localhost+https") << "localhost"
+                                     << "https" << QNetworkReply::ProxyConnectionRefusedError;
+#endif
+}
+
+void tst_QNetworkReply::qtbug68821proxyError()
+{
+    QTcpServer proxyServer;
+    QVERIFY(proxyServer.listen());
+    quint16 proxyPort = proxyServer.serverPort();
+    proxyServer.close();
+
+    QFETCH(QString, proxyHost);
+    QNetworkProxy proxy(QNetworkProxy::HttpProxy, proxyHost, proxyPort);
+
+    manager.setProxy(proxy);
+
+    QFETCH(QString, scheme);
+    QNetworkReply *reply = manager.get(QNetworkRequest(QUrl(scheme + "://example.com")));
+    QSignalSpy spy(reply, &QNetworkReply::errorOccurred);
+    QVERIFY(spy.isValid());
+
+    QVERIFY(spy.wait(15000));
+
+    QFETCH(QNetworkReply::NetworkError, error);
+    QCOMPARE(spy.count(), 1);
+    QCOMPARE(spy.at(0).at(0), error);
+}
+
 // NOTE: This test must be last testcase in tst_qnetworkreply!
 void tst_QNetworkReply::parentingRepliesToTheApp()
 {