Fix a number of bugs with windows system proxies

TcpServer requests always returned no proxy, even if socks was available
Tag handling was broken for empty tag (if system proxies were tagged)
Tag handling was broken for unknown tags - now handled the same as if
    no tag was given at all.
When there are different proxies for http and https, windows returns
the http proxy first. However we should prefer to use the https proxy
for general sockets, as it's more likely to support the CONNECT method.

Change-Id: I55dcadf2e142367e857f94e55fdbb0c4ddb513a3
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@nokia.com>
Reviewed-by: Robin Burchell <robin+qt@viroteck.net>
Reviewed-by: Richard J. Moore <rich@kde.org>
Reviewed-by: Shane Kearns <shane.kearns@accenture.com>

src/network/kernel/qnetworkproxy_win.cpp

@@ -146,7 +146,7 @@ static QStringList splitSpaceSemicolon(const QString &source)
 static bool isBypassed(const QString &host, const QStringList &bypassList)
 {
     if (host.isEmpty())
-        return true;
+        return false;
 
     bool isSimple = !host.contains(QLatin1Char('.')) && !host.contains(QLatin1Char(':'));
 
@@ -171,6 +171,51 @@ static bool isBypassed(const QString &host, const QStringList &bypassList)
     return false;
 }
 
+static QList<QNetworkProxy> filterProxyListByCapabilities(const QList<QNetworkProxy> &proxyList, const QNetworkProxyQuery &query)
+{
+    QNetworkProxy::Capabilities requiredCaps;
+    switch (query.queryType()) {
+    case QNetworkProxyQuery::TcpSocket:
+        requiredCaps = QNetworkProxy::TunnelingCapability;
+        break;
+    case QNetworkProxyQuery::UdpSocket:
+        requiredCaps = QNetworkProxy::UdpTunnelingCapability;
+        break;
+    case QNetworkProxyQuery::TcpServer:
+        requiredCaps = QNetworkProxy::ListeningCapability;
+        break;
+    default:
+        return proxyList;
+        break;
+    }
+    QList<QNetworkProxy> result;
+    foreach (const QNetworkProxy& proxy, proxyList) {
+        if (proxy.capabilities() & requiredCaps)
+            result.append(proxy);
+    }
+    return result;
+}
+
+static QList<QNetworkProxy> removeDuplicateProxies(const QList<QNetworkProxy> &proxyList)
+{
+    QList<QNetworkProxy> result;
+     foreach (QNetworkProxy proxy, proxyList) {
+         bool append = true;
+         for (int i=0; i < result.count(); i++) {
+             if (proxy.hostName() == result.at(i).hostName()
+                 && proxy.port() == result.at(i).port()) {
+                     append = false;
+                     // HttpProxy trumps FtpCachingProxy or HttpCachingProxy on the same host/port
+                     if (proxy.type() == QNetworkProxy::HttpProxy)
+                         result[i] = proxy;
+             }
+         }
+         if (append)
+             result.append(proxy);
+     }
+     return result;
+}
+
 static QList<QNetworkProxy> parseServerList(const QNetworkProxyQuery &query, const QStringList &proxyList)
 {
     // Reference documentation from Microsoft:
@@ -183,6 +228,9 @@ static QList<QNetworkProxy> parseServerList(const QNetworkProxyQuery &query, con
     // The second scheme, if present, overrides the proxy type
 
     QList<QNetworkProxy> result;
+    QHash<QString, QNetworkProxy> taggedProxies;
+    const QString requiredTag = query.protocolTag();
+    bool checkTags = !requiredTag.isEmpty() && query.queryType() != QNetworkProxyQuery::TcpServer; //windows tags are only for clients
     foreach (const QString &entry, proxyList) {
         int server = 0;
 
@@ -191,11 +239,9 @@ static QList<QNetworkProxy> parseServerList(const QNetworkProxyQuery &query, con
 
         int pos = entry.indexOf(QLatin1Char('='));
         QStringRef scheme;
+        QStringRef protocolTag;
         if (pos != -1) {
-            scheme = entry.leftRef(pos);
-            if (scheme != query.protocolTag())
-                continue;
-
+            scheme = protocolTag = entry.leftRef(pos);
             server = pos + 1;
         }
         pos = entry.indexOf(QLatin1String("://"), server);
@@ -233,9 +279,32 @@ static QList<QNetworkProxy> parseServerList(const QNetworkProxyQuery &query, con
         }
 
         result << QNetworkProxy(proxyType, entry.mid(server, pos - server), port);
+        if (!protocolTag.isEmpty())
+            taggedProxies.insert(protocolTag.toString(), result.last());
     }
 
-    return result;
+    if (checkTags && taggedProxies.contains(requiredTag)) {
+        if (query.queryType() == QNetworkProxyQuery::UrlRequest) {
+            result.clear();
+            result.append(taggedProxies.value(requiredTag));
+            return result;
+        } else {
+            result.prepend(taggedProxies.value(requiredTag));
+        }
+    }
+    if (!checkTags || requiredTag != QLatin1String("http")) {
+        // if there are different http proxies for http and https, prefer the https one (more likely to be capable of CONNECT)
+        QNetworkProxy httpProxy = taggedProxies.value(QLatin1String("http"));
+        QNetworkProxy httpsProxy = taggedProxies.value(QLatin1String("http"));
+        if (httpProxy != httpsProxy && httpProxy.type() == QNetworkProxy::HttpProxy && httpsProxy.type() == QNetworkProxy::HttpProxy) {
+            for (int i = 0; i < result.count(); i++) {
+                if (httpProxy == result.at(i))
+                    result[i].setType(QNetworkProxy::HttpCachingProxy);
+            }
+        }
+    }
+    result = filterProxyListByCapabilities(result, query);
+    return removeDuplicateProxies(result);
 }
 
 class QWindowsSystemProxy