Network: Use QHttpHeaders in QHttpHeaderParser

QHttpHeaderParser::headers() method is changed to return QHttpHeaders.
QAuthenticatorPrivate::parseHttpResponse() method is changed to work with QHttpHeaders.
QHttpNetworkHeader::header() method is updated to return QHttpHeaders.
Tests are updated.

Task-number: QTBUG-120133
Change-Id: I20a18b509acd7a8b8d93884cff8349519d64293e
Reviewed-by: Ievgenii Meshcheriakov <ievgenii.meshcheriakov@qt.io>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Øystein Heskestad <oystein.heskestad@qt.io>

27 files changed, 194 insertions, 192 deletions

diff --git a/src/network/CMakeLists.txt b/src/network/CMakeLists.txt
index 82b59af329..ee61bc6113 100644
--- a/src/network/CMakeLists.txt
+++ b/src/network/CMakeLists.txt
@@ -20,6 +20,7 @@ qt_internal_add_module(Network
         access/qnetworkcookie.cpp access/qnetworkcookie.h access/qnetworkcookie_p.h
         access/qnetworkcookiejar.cpp access/qnetworkcookiejar.h access/qnetworkcookiejar_p.h
         access/qnetworkfile.cpp access/qnetworkfile_p.h
+        access/qhttpheaders.cpp access/qhttpheaders.h
         access/qhttpheaderparser.cpp access/qhttpheaderparser_p.h
         access/qnetworkreply.cpp access/qnetworkreply.h access/qnetworkreply_p.h
         access/qnetworkreplydataimpl.cpp access/qnetworkreplydataimpl_p.h
@@ -124,7 +125,6 @@ qt_internal_extend_target(Network CONDITION QT_FEATURE_http
         access/qhttp2configuration.cpp access/qhttp2configuration.h
         access/qhttp2connection.cpp access/qhttp2connection_p.h
         access/qhttp2protocolhandler.cpp access/qhttp2protocolhandler_p.h
-        access/qhttpheaders.cpp access/qhttpheaders.h
         access/qhttpmultipart.cpp access/qhttpmultipart.h access/qhttpmultipart_p.h
         access/qhttpnetworkconnection.cpp access/qhttpnetworkconnection_p.h
         access/qhttpnetworkconnectionchannel.cpp access/qhttpnetworkconnectionchannel_p.h
diff --git a/src/network/access/http2/http2protocol.cpp b/src/network/access/http2/http2protocol.cpp
index 1e7291e48e..7d582497ab 100644
--- a/src/network/access/http2/http2protocol.cpp
+++ b/src/network/access/http2/http2protocol.cpp
@@ -184,14 +184,13 @@ QNetworkReply::NetworkError qt_error(quint32 errorCode)
 
 bool is_protocol_upgraded(const QHttpNetworkReply &reply)
 {
-    if (reply.statusCode() == 101) {
-        // Do some minimal checks here - we expect 'Upgrade: h2c' to be found.
-        const auto &header = reply.header();
-        for (const QPair<QByteArray, QByteArray> &field : header) {
-            if (field.first.compare("upgrade", Qt::CaseInsensitive) == 0 &&
-                    field.second.compare("h2c", Qt::CaseInsensitive) == 0)
-                return true;
-        }
+    if (reply.statusCode() != 101)
+        return false;
+
+    // Do some minimal checks here - we expect 'Upgrade: h2c' to be found.
+    for (const auto &v : reply.header().values(QHttpHeaders::WellKnownHeader::Upgrade)) {
+        if (v.compare("h2c", Qt::CaseInsensitive) == 0)
+            return true;
     }
 
     return false;
diff --git a/src/network/access/qhsts.cpp b/src/network/access/qhsts.cpp
index 13755d0003..21ed08ce4a 100644
--- a/src/network/access/qhsts.cpp
+++ b/src/network/access/qhsts.cpp
@@ -3,6 +3,8 @@
 
 #include "qhsts_p.h"
 
+#include "qhttpheaders.h"
+
 #include "QtCore/private/qipaddress_p.h"
 #include "QtCore/qlist.h"
 
@@ -40,7 +42,7 @@ static bool is_valid_domain_name(const QString &host)
     return true;
 }
 
-void QHstsCache::updateFromHeaders(const QList<QPair<QByteArray, QByteArray>> &headers,
+void QHstsCache::updateFromHeaders(const QHttpHeaders &headers,
                                    const QUrl &url)
 {
     if (!url.isValid())
@@ -324,27 +326,25 @@ quoted-pair    = "\" CHAR
 
 */
 
-bool QHstsHeaderParser::parse(const QList<QPair<QByteArray, QByteArray>> &headers)
+bool QHstsHeaderParser::parse(const QHttpHeaders &headers)
 {
-    for (const auto &h : headers) {
-        // We compare directly because header name was already 'trimmed' for us:
-        if (h.first.compare("Strict-Transport-Security", Qt::CaseInsensitive) == 0) {
-            header = h.second;
-            // RFC6797, 8.1:
-            //
-            //  The UA MUST ignore any STS header fields not conforming to the
-            // grammar specified in Section 6.1 ("Strict-Transport-Security HTTP
-            // Response Header Field").
-            //
-            // If a UA receives more than one STS header field in an HTTP
-            // response message over secure transport, then the UA MUST process
-            // only the first such header field.
-            //
-            // We read this as: ignore all invalid headers and take the first valid:
-            if (parseSTSHeader() && maxAgeFound) {
-                expiry = QDateTime::currentDateTimeUtc().addSecs(maxAge);
-                return true;
-            }
+    for (const auto &value : headers.values(
+                 QHttpHeaders::WellKnownHeader::StrictTransportSecurity)) {
+        header = value;
+        // RFC6797, 8.1:
+        //
+        //  The UA MUST ignore any STS header fields not conforming to the
+        // grammar specified in Section 6.1 ("Strict-Transport-Security HTTP
+        // Response Header Field").
+        //
+        // If a UA receives more than one STS header field in an HTTP
+        // response message over secure transport, then the UA MUST process
+        // only the first such header field.
+        //
+        // We read this as: ignore all invalid headers and take the first valid:
+        if (parseSTSHeader() && maxAgeFound) {
+            expiry = QDateTime::currentDateTimeUtc().addSecs(maxAge);
+            return true;
         }
     }
 
diff --git a/src/network/access/qhsts_p.h b/src/network/access/qhsts_p.h
index 96d4ee8dc5..ff9378197b 100644
--- a/src/network/access/qhsts_p.h
+++ b/src/network/access/qhsts_p.h
@@ -31,11 +31,13 @@
 
 QT_BEGIN_NAMESPACE
 
+class QHttpHeaders;
+
 class Q_AUTOTEST_EXPORT QHstsCache
 {
 public:
 
-    void updateFromHeaders(const QList<QPair<QByteArray, QByteArray>> &headers,
+    void updateFromHeaders(const QHttpHeaders &headers,
                            const QUrl &url);
     void updateFromPolicies(const QList<QHstsPolicy> &hosts);
     void updateKnownHost(const QUrl &url, const QDateTime &expires,
@@ -90,7 +92,7 @@ class Q_AUTOTEST_EXPORT QHstsHeaderParser
 {
 public:
 
-    bool parse(const QList<QPair<QByteArray, QByteArray>> &headers);
+    bool parse(const QHttpHeaders &headers);
 
     QDateTime expirationDate() const { return expiry; }
     bool includeSubDomains() const { return subDomainsFound; }
diff --git a/src/network/access/qhttp2protocolhandler.cpp b/src/network/access/qhttp2protocolhandler.cpp
index 60f7ea12a6..4bb057b209 100644
--- a/src/network/access/qhttp2protocolhandler.cpp
+++ b/src/network/access/qhttp2protocolhandler.cpp
@@ -60,7 +60,7 @@ HPack::HttpHeader build_headers(const QHttpNetworkRequest &request, quint32 maxH
     if (size.second > maxHeaderListSize)
         return HttpHeader(); // Bad, we cannot send this request ...
 
-    const auto requestHeader = request.header();
+    const auto requestHeader = request.header().toListOfPairs();
     for (const auto &field : requestHeader) {
         const HeaderSize delta = entry_size(field.first, field.second);
         if (!delta.first) // Overflow???
diff --git a/src/network/access/qhttpheaderparser.cpp b/src/network/access/qhttpheaderparser.cpp
index cb6b479543..0b7882c18a 100644
--- a/src/network/access/qhttpheaderparser.cpp
+++ b/src/network/access/qhttpheaderparser.cpp
@@ -52,11 +52,11 @@ bool QHttpHeaderParser::parseHeaders(QByteArrayView header)
     if (header.size() - (header.endsWith("\r\n") ? 2 : 1) > maxTotalSize)
         return false;
 
-    QList<QPair<QByteArray, QByteArray>> result;
+    QHttpHeaders result;
     while (!header.empty()) {
         const qsizetype colon = header.indexOf(':');
         if (colon == -1) // if no colon check if empty headers
-            return result.empty() && (header == "\n" || header == "\r\n");
+            return result.isEmpty() && (header == "\n" || header == "\r\n");
         if (result.size() >= maxFieldCount)
             return false;
         QByteArrayView name = header.first(colon);
@@ -82,7 +82,7 @@ bool QHttpHeaderParser::parseHeaders(QByteArrayView header)
             header = header.sliced(endLine + 1);
         } while (hSpaceStart(header));
         Q_ASSERT(name.size() + 1 + value.size() <= maxFieldSize);
-        result.append(qMakePair(name.toByteArray(), value));
+        result.append(name, value);
     }
 
     fields = result;
@@ -128,25 +128,15 @@ bool QHttpHeaderParser::parseStatus(QByteArrayView status)
     return ok && uint(majorVersion) <= 9 && uint(minorVersion) <= 9;
 }
 
-const QList<QPair<QByteArray, QByteArray> >& QHttpHeaderParser::headers() const
+const QHttpHeaders& QHttpHeaderParser::headers() const
 {
     return fields;
 }
 
-static auto firstEqualsName(QByteArrayView name)
-{
-    return [name](const QPair<QByteArray, QByteArray> &header) {
-        return name.compare(header.first, Qt::CaseInsensitive) == 0;
-    };
-}
-
 QByteArray QHttpHeaderParser::firstHeaderField(QByteArrayView name,
                                                const QByteArray &defaultValue) const
 {
-    const auto it = std::find_if(fields.begin(), fields.end(), firstEqualsName(name));
-    if (it != fields.end())
-        return it->second;
-    return defaultValue;
+    return fields.value(name, defaultValue).toByteArray();
 }
 
 QByteArray QHttpHeaderParser::combinedHeaderValue(QByteArrayView name, const QByteArray &defaultValue) const
@@ -159,33 +149,28 @@ QByteArray QHttpHeaderParser::combinedHeaderValue(QByteArrayView name, const QBy
 
 QList<QByteArray> QHttpHeaderParser::headerFieldValues(QByteArrayView name) const
 {
-    QList<QByteArray> result;
-    for (auto it = fields.constBegin(); it != fields.constEnd(); ++it)
-        if (name.compare(it->first, Qt::CaseInsensitive) == 0)
-            result += it->second;
-
-    return result;
+    return fields.values(name);
 }
 
 void QHttpHeaderParser::removeHeaderField(QByteArrayView name)
 {
-    fields.removeIf(firstEqualsName(name));
+    fields.removeAll(name);
 }
 
 void QHttpHeaderParser::setHeaderField(const QByteArray &name, const QByteArray &data)
 {
     removeHeaderField(name);
-    fields.append(qMakePair(name, data));
+    fields.append(name, data);
 }
 
 void QHttpHeaderParser::prependHeaderField(const QByteArray &name, const QByteArray &data)
 {
-    fields.prepend(qMakePair(name, data));
+    fields.insert(0, name, data);
 }
 
 void QHttpHeaderParser::appendHeaderField(const QByteArray &name, const QByteArray &data)
 {
-    fields.append(qMakePair(name, data));
+    fields.append(name, data);
 }
 
 void QHttpHeaderParser::clearHeaders()
diff --git a/src/network/access/qhttpheaderparser_p.h b/src/network/access/qhttpheaderparser_p.h
index 50ca83693a..5e8f3c8130 100644
--- a/src/network/access/qhttpheaderparser_p.h
+++ b/src/network/access/qhttpheaderparser_p.h
@@ -16,6 +16,7 @@
 //
 
 #include <QtNetwork/private/qtnetworkglobal_p.h>
+#include <QtNetwork/qhttpheaders.h>
 
 #include <QByteArray>
 #include <QList>
@@ -52,7 +53,7 @@ public:
     bool parseHeaders(QByteArrayView headers);
     bool parseStatus(QByteArrayView status);
 
-    const QList<QPair<QByteArray, QByteArray> >& headers() const;
+    const QHttpHeaders& headers() const;
     void setStatusCode(int code);
     int getStatusCode() const;
     int getMajorVersion() const;
@@ -83,7 +84,7 @@ public:
     qsizetype maxHeaderFields() const { return maxFieldCount; }
 
 private:
-    QList<QPair<QByteArray, QByteArray> > fields;
+    QHttpHeaders fields;
     QString reasonPhrase;
     int statusCode;
     int majorVersion;
diff --git a/src/network/access/qhttpnetworkconnection.cpp b/src/network/access/qhttpnetworkconnection.cpp
index 1f2fb6d03c..b8a49a926d 100644
--- a/src/network/access/qhttpnetworkconnection.cpp
+++ b/src/network/access/qhttpnetworkconnection.cpp
@@ -411,7 +411,7 @@ bool QHttpNetworkConnectionPrivate::handleAuthenticateChallenge(QAbstractSocket
 
     resend = false;
     //create the response header to be used with QAuthenticatorPrivate.
-    QList<QPair<QByteArray, QByteArray> > fields = reply->header();
+    const auto headers = reply->header();
 
     // Check that any of the proposed authenticate methods are supported
     const QByteArray header = isProxy ? "proxy-authenticate" : "www-authenticate";
@@ -427,7 +427,7 @@ bool QHttpNetworkConnectionPrivate::handleAuthenticateChallenge(QAbstractSocket
         if (auth->isNull())
             auth->detach();
         QAuthenticatorPrivate *priv = QAuthenticatorPrivate::getPrivate(*auth);
-        priv->parseHttpResponse(fields, isProxy, reply->url().host());
+        priv->parseHttpResponse(headers, isProxy, reply->url().host());
         // Update method in case it changed
         if (priv->method == QAuthenticatorPrivate::None)
             return false;
@@ -523,12 +523,9 @@ QHttpNetworkConnectionPrivate::parseRedirectResponse(QHttpNetworkReply *reply)
         return {{}, QNetworkReply::NoError};
 
     QUrl redirectUrl;
-    const QList<QPair<QByteArray, QByteArray> > fields = reply->header();
-    for (const QNetworkReply::RawHeaderPair &header : fields) {
-        if (header.first.compare("location", Qt::CaseInsensitive) == 0) {
-            redirectUrl = QUrl::fromEncoded(header.second);
-            break;
-        }
+    const QHttpHeaders fields = reply->header();
+    if (const auto h = fields.values(QHttpHeaders::WellKnownHeader::Location); !h.empty()) {
+        redirectUrl = QUrl::fromEncoded(h.first());
     }
 
     // If the location url is invalid/empty, we return ProtocolUnknownError
diff --git a/src/network/access/qhttpnetworkheader.cpp b/src/network/access/qhttpnetworkheader.cpp
index 8ef664c012..7f9c94dc9c 100644
--- a/src/network/access/qhttpnetworkheader.cpp
+++ b/src/network/access/qhttpnetworkheader.cpp
@@ -53,7 +53,7 @@ void QHttpNetworkHeaderPrivate::prependHeaderField(const QByteArray &name, const
     parser.prependHeaderField(name, data);
 }
 
-QList<QPair<QByteArray, QByteArray> > QHttpNetworkHeaderPrivate::headers() const
+QHttpHeaders QHttpNetworkHeaderPrivate::headers() const
 {
     return parser.headers();
 }
diff --git a/src/network/access/qhttpnetworkheader_p.h b/src/network/access/qhttpnetworkheader_p.h
index 57c06eb95c..afbc6cb6fe 100644
--- a/src/network/access/qhttpnetworkheader_p.h
+++ b/src/network/access/qhttpnetworkheader_p.h
@@ -17,6 +17,7 @@
 
 #include <QtNetwork/private/qtnetworkglobal_p.h>
 #include <QtNetwork/private/qhttpheaderparser_p.h>
+#include <QtNetwork/qhttpheaders.h>
 
 #include <qshareddata.h>
 #include <qurl.h>
@@ -40,7 +41,7 @@ public:
     virtual qint64 contentLength() const = 0;
     virtual void setContentLength(qint64 length) = 0;
 
-    virtual QList<QPair<QByteArray, QByteArray> > header() const = 0;
+    virtual QHttpHeaders header() const = 0;
     virtual QByteArray headerField(QByteArrayView name, const QByteArray &defaultValue = QByteArray()) const = 0;
     virtual void setHeaderField(const QByteArray &name, const QByteArray &data) = 0;
 };
@@ -61,7 +62,7 @@ public:
     void setHeaderField(const QByteArray &name, const QByteArray &data);
     void prependHeaderField(const QByteArray &name, const QByteArray &data);
     void clearHeaders();
-    QList<QPair<QByteArray, QByteArray> > headers() const;
+    QHttpHeaders headers() const;
     bool operator==(const QHttpNetworkHeaderPrivate &other) const;
 
 };
diff --git a/src/network/access/qhttpnetworkreply.cpp b/src/network/access/qhttpnetworkreply.cpp
index aad41e9a14..6d82e81322 100644
--- a/src/network/access/qhttpnetworkreply.cpp
+++ b/src/network/access/qhttpnetworkreply.cpp
@@ -67,7 +67,7 @@ void QHttpNetworkReply::setContentLength(qint64 length)
     d->setContentLength(length);
 }
 
-QList<QPair<QByteArray, QByteArray> > QHttpNetworkReply::header() const
+QHttpHeaders QHttpNetworkReply::header() const
 {
     return d_func()->parser.headers();
 }
diff --git a/src/network/access/qhttpnetworkreply_p.h b/src/network/access/qhttpnetworkreply_p.h
index 54ff53452b..c1b155caa7 100644
--- a/src/network/access/qhttpnetworkreply_p.h
+++ b/src/network/access/qhttpnetworkreply_p.h
@@ -41,6 +41,7 @@ Q_MOC_INCLUDE(<QtNetwork/QNetworkProxy>)
 Q_MOC_INCLUDE(<QtNetwork/QAuthenticator>)
 
 #include <private/qdecompresshelper_p.h>
+#include <QtNetwork/qhttpheaders.h>
 
 #include <QtCore/qpointer.h>
 
@@ -72,7 +73,7 @@ public:
     qint64 contentLength() const override;
     void setContentLength(qint64 length) override;
 
-    QList<QPair<QByteArray, QByteArray> > header() const override;
+    QHttpHeaders header() const override;
     QByteArray headerField(QByteArrayView name, const QByteArray &defaultValue = QByteArray()) const override;
     void setHeaderField(const QByteArray &name, const QByteArray &data) override;
     void appendHeaderField(const QByteArray &name, const QByteArray &data);
diff --git a/src/network/access/qhttpnetworkrequest.cpp b/src/network/access/qhttpnetworkrequest.cpp
index c32a75eccb..bc3eb67adc 100644
--- a/src/network/access/qhttpnetworkrequest.cpp
+++ b/src/network/access/qhttpnetworkrequest.cpp
@@ -112,7 +112,7 @@ QByteArray QHttpNetworkRequest::uri(bool throughProxy) const
 
 QByteArray QHttpNetworkRequestPrivate::header(const QHttpNetworkRequest &request, bool throughProxy)
 {
-    const QList<QPair<QByteArray, QByteArray> > fields = request.header();
+    const QList<QPair<QByteArray, QByteArray> > fields = request.header().toListOfPairs();
     QByteArray ba;
     ba.reserve(40 + fields.size()*25); // very rough lower bound estimation
 
@@ -235,7 +235,7 @@ void QHttpNetworkRequest::setContentLength(qint64 length)
     d->setContentLength(length);
 }
 
-QList<QPair<QByteArray, QByteArray> > QHttpNetworkRequest::header() const
+QHttpHeaders QHttpNetworkRequest::header() const
 {
     return d->parser.headers();
 }
diff --git a/src/network/access/qhttpnetworkrequest_p.h b/src/network/access/qhttpnetworkrequest_p.h
index 6cf8ca2401..131885f6d2 100644
--- a/src/network/access/qhttpnetworkrequest_p.h
+++ b/src/network/access/qhttpnetworkrequest_p.h
@@ -65,7 +65,7 @@ public:
     qint64 contentLength() const override;
     void setContentLength(qint64 length) override;
 
-    QList<QPair<QByteArray, QByteArray> > header() const override;
+    QHttpHeaders header() const override;
     QByteArray headerField(QByteArrayView name, const QByteArray &defaultValue = QByteArray()) const override;
     void setHeaderField(const QByteArray &name, const QByteArray &data) override;
     void prependHeaderField(const QByteArray &name, const QByteArray &data);
diff --git a/src/network/access/qhttpthreaddelegate_p.h b/src/network/access/qhttpthreaddelegate_p.h
index 0d052e2450..38e9fb4d78 100644
--- a/src/network/access/qhttpthreaddelegate_p.h
+++ b/src/network/access/qhttpthreaddelegate_p.h
@@ -33,6 +33,7 @@
 #include "private/qnoncontiguousbytedevice_p.h"
 #include "qnetworkaccessauthenticationmanager_p.h"
 #include <QtNetwork/private/http2protocol_p.h>
+#include <QtNetwork/qhttpheaders.h>
 
 QT_REQUIRE_CONFIG(http);
 
@@ -74,7 +75,7 @@ public:
 
     // outgoing, Retrieved in the synchronous HTTP case
     QByteArray synchronousDownloadData;
-    QList<QPair<QByteArray,QByteArray> > incomingHeaders;
+    QHttpHeaders incomingHeaders;
     int incomingStatusCode;
     QString incomingReasonPhrase;
     bool isPipeliningUsed;
@@ -112,7 +113,7 @@ signals:
 #endif
     void socketStartedConnecting();
     void requestSent();
-    void downloadMetaData(const QList<QPair<QByteArray,QByteArray> > &, int, const QString &, bool,
+    void downloadMetaData(const QHttpHeaders &, int, const QString &, bool,
                           QSharedPointer<char>, qint64, qint64, bool, bool);
     void downloadProgress(qint64, qint64);
     void downloadData(const QByteArray &);
diff --git a/src/network/access/qnetworkreplyhttpimpl.cpp b/src/network/access/qnetworkreplyhttpimpl.cpp
index 53bc0f5283..84d9e08b91 100644
--- a/src/network/access/qnetworkreplyhttpimpl.cpp
+++ b/src/network/access/qnetworkreplyhttpimpl.cpp
@@ -1325,7 +1325,7 @@ void QNetworkReplyHttpImplPrivate::checkForRedirect(const int statusCode)
     }
 }
 
-void QNetworkReplyHttpImplPrivate::replyDownloadMetaData(const QList<QPair<QByteArray,QByteArray> > &hm,
+void QNetworkReplyHttpImplPrivate::replyDownloadMetaData(const QHttpHeaders &hm,
                                                          int sc, const QString &rp, bool pu,
                                                          QSharedPointer<char> db,
                                                          qint64 contentLength,
@@ -1364,7 +1364,7 @@ void QNetworkReplyHttpImplPrivate::replyDownloadMetaData(const QList<QPair<QByte
     const bool autoDecompress = request.rawHeader("accept-encoding").isEmpty();
     const bool shouldDecompress = isCompressed && autoDecompress;
     // reconstruct the HTTP header
-    for (const auto &[key, originValue] : hm) {
+    for (const auto &[key, originValue] : hm.toListOfPairs()) {
         QByteArray value = q->rawHeader(key);
 
         // Reset any previous "location" header set in the reply. In case of
diff --git a/src/network/access/qnetworkreplyhttpimpl_p.h b/src/network/access/qnetworkreplyhttpimpl_p.h
index 11897d1420..e00c43bdb3 100644
--- a/src/network/access/qnetworkreplyhttpimpl_p.h
+++ b/src/network/access/qnetworkreplyhttpimpl_p.h
@@ -244,7 +244,7 @@ public:
     // From HTTP thread:
     void replyDownloadData(QByteArray);
     void replyFinished();
-    void replyDownloadMetaData(const QList<QPair<QByteArray,QByteArray> > &, int, const QString &,
+    void replyDownloadMetaData(const QHttpHeaders &, int, const QString &,
                                bool, QSharedPointer<char>, qint64, qint64, bool, bool);
     void replyDownloadProgressSlot(qint64,qint64);
     void httpAuthenticationRequired(const QHttpNetworkRequest &request, QAuthenticator *auth);
diff --git a/src/network/kernel/qauthenticator.cpp b/src/network/kernel/qauthenticator.cpp
index e2ad91f171..e42450d7e5 100644
--- a/src/network/kernel/qauthenticator.cpp
+++ b/src/network/kernel/qauthenticator.cpp
@@ -14,6 +14,7 @@
 #include <qstring.h>
 #include <qdatetime.h>
 #include <qrandom.h>
+#include <QtNetwork/qhttpheaders.h>
 
 #ifdef Q_OS_WIN
 #include <qmutex.h>
@@ -444,14 +445,14 @@ static bool verifyDigestMD5(QByteArrayView value)
     return true; // assume it's ok if algorithm is not specified
 }
 
-void QAuthenticatorPrivate::parseHttpResponse(const QList<QPair<QByteArray, QByteArray>> &values,
+void QAuthenticatorPrivate::parseHttpResponse(const QHttpHeaders &headers,
                                               bool isProxy, QStringView host)
 {
 #if !QT_CONFIG(gssapi)
     Q_UNUSED(host);
 #endif
-    const auto search = isProxy ?
-            QByteArrayView("proxy-authenticate") : QByteArrayView("www-authenticate");
+    const auto search = isProxy ? QHttpHeaders::WellKnownHeader::ProxyAuthenticate
+                                : QHttpHeaders::WellKnownHeader::WWWAuthenticate;
 
     method = None;
     /*
@@ -465,23 +466,21 @@ void QAuthenticatorPrivate::parseHttpResponse(const QList<QPair<QByteArray, QByt
     */
 
     QByteArrayView headerVal;
-    for (const auto &current : values) {
-        if (current.first.compare(search, Qt::CaseInsensitive) != 0)
-            continue;
-        const QLatin1StringView str(current.second);
+    for (const auto &current : headers.values(search)) {
+        const QLatin1StringView str(current);
         if (method < Basic && str.startsWith("basic"_L1, Qt::CaseInsensitive)) {
             method = Basic;
-            headerVal = QByteArrayView(current.second).mid(6);
+            headerVal = QByteArrayView(current).mid(6);
         } else if (method < Ntlm && str.startsWith("ntlm"_L1, Qt::CaseInsensitive)) {
             method = Ntlm;
-            headerVal = QByteArrayView(current.second).mid(5);
+            headerVal = QByteArrayView(current).mid(5);
         } else if (method < DigestMd5 && str.startsWith("digest"_L1, Qt::CaseInsensitive)) {
             // Make sure the algorithm is actually MD5 before committing to it:
-            if (!verifyDigestMD5(QByteArrayView(current.second).sliced(7)))
+            if (!verifyDigestMD5(QByteArrayView(current).sliced(7)))
                 continue;
 
             method = DigestMd5;
-            headerVal = QByteArrayView(current.second).mid(7);
+            headerVal = QByteArrayView(current).mid(7);
         } else if (method < Negotiate && str.startsWith("negotiate"_L1, Qt::CaseInsensitive)) {
 #if QT_CONFIG(sspi) || QT_CONFIG(gssapi) // if it's not supported then we shouldn't try to use it
 #if QT_CONFIG(gssapi)
@@ -492,7 +491,7 @@ void QAuthenticatorPrivate::parseHttpResponse(const QList<QPair<QByteArray, QByt
                 continue;
 #endif
             method = Negotiate;
-            headerVal = QByteArrayView(current.second).mid(10);
+            headerVal = QByteArrayView(current).mid(10);
 #endif
         }
     }
diff --git a/src/network/kernel/qauthenticator_p.h b/src/network/kernel/qauthenticator_p.h
index 7c4fe736b5..bc16139941 100644
--- a/src/network/kernel/qauthenticator_p.h
+++ b/src/network/kernel/qauthenticator_p.h
@@ -26,6 +26,7 @@
 QT_BEGIN_NAMESPACE
 
 class QHttpResponseHeader;
+class QHttpHeaders;
 #if QT_CONFIG(sspi) // SSPI
 class QSSPIWindowsHandles;
 #elif QT_CONFIG(gssapi) // GSSAPI
@@ -80,8 +81,7 @@ public:
     static QHash<QByteArray, QByteArray>
     parseDigestAuthenticationChallenge(QByteArrayView challenge);
 
-    void parseHttpResponse(const QList<QPair<QByteArray, QByteArray>> &, bool isProxy,
-                           QStringView host);
+    void parseHttpResponse(const QHttpHeaders &headers, bool isProxy, QStringView host);
     void updateCredentials();
 
     static bool isMethodSupported(QByteArrayView method);
diff --git a/src/network/socket/qhttpsocketengine.cpp b/src/network/socket/qhttpsocketengine.cpp
index c339912240..a700023bd5 100644
--- a/src/network/socket/qhttpsocketengine.cpp
+++ b/src/network/socket/qhttpsocketengine.cpp
@@ -553,7 +553,8 @@ void QHttpSocketEngine::slotSocketReadNotification()
             d->authenticator.detach();
         priv = QAuthenticatorPrivate::getPrivate(d->authenticator);
 
-        priv->parseHttpResponse(d->reply->header(), true, d->proxy.hostName());
+        const auto headers = d->reply->header();
+        priv->parseHttpResponse(headers, true, d->proxy.hostName());
 
         if (priv->phase == QAuthenticatorPrivate::Invalid) {
             // problem parsing the reply
diff --git a/tests/auto/network/access/hsts/tst_qhsts.cpp b/tests/auto/network/access/hsts/tst_qhsts.cpp
index 97a2d2889e..d81bc3e3e3 100644
--- a/tests/auto/network/access/hsts/tst_qhsts.cpp
+++ b/tests/auto/network/access/hsts/tst_qhsts.cpp
@@ -9,6 +9,7 @@
 #include <QtCore/qpair.h>
 #include <QtCore/qurl.h>
 
+#include <QtNetwork/qhttpheaders.h>
 #include <QtNetwork/private/qhstsstore_p.h>
 #include <QtNetwork/private/qhsts_p.h>
 
@@ -189,110 +190,108 @@ void tst_QHsts::testPolicyExpiration()
 void tst_QHsts::testSTSHeaderParser()
 {
     QHstsHeaderParser parser;
-    using Header = QPair<QByteArray, QByteArray>;
-    using Headers = QList<Header>;
 
     QVERIFY(!parser.includeSubDomains());
     QVERIFY(!parser.expirationDate().isValid());
-    Headers list;
-    QVERIFY(!parser.parse(list));
+    QHttpHeaders headers;
+    QVERIFY(!parser.parse(headers));
     QVERIFY(!parser.includeSubDomains());
     QVERIFY(!parser.expirationDate().isValid());
 
-    list << Header("Strict-Transport-security", "200");
-    QVERIFY(!parser.parse(list));
+    headers.append("Strict-Transport-security", "200");
+    QVERIFY(!parser.parse(headers));
     QVERIFY(!parser.includeSubDomains());
     QVERIFY(!parser.expirationDate().isValid());
 
     // This header is missing REQUIRED max-age directive, so we'll ignore it:
-    list << Header("Strict-Transport-Security", "includeSubDomains");
-    QVERIFY(!parser.parse(list));
+    headers.append("Strict-Transport-Security", "includeSubDomains");
+    QVERIFY(!parser.parse(headers));
     QVERIFY(!parser.includeSubDomains());
     QVERIFY(!parser.expirationDate().isValid());
 
-    list.pop_back();
-    list << Header("Strict-Transport-Security", "includeSubDomains;max-age=1000");
-    QVERIFY(parser.parse(list));
+    headers.removeAt(headers.size() - 1);
+    headers.append("Strict-Transport-Security", "includeSubDomains;max-age=1000");
+    QVERIFY(parser.parse(headers));
     QVERIFY(parser.expirationDate() > QDateTime::currentDateTimeUtc());
     QVERIFY(parser.includeSubDomains());
 
-    list.pop_back();
-    list << Header("strict-transport-security", "includeSubDomains;max-age=1000");
-    QVERIFY(parser.parse(list));
+    headers.removeAt(headers.size() - 1);
+    headers.append("strict-transport-security", "includeSubDomains;max-age=1000");
+    QVERIFY(parser.parse(headers));
     QVERIFY(parser.expirationDate() > QDateTime::currentDateTimeUtc());
     QVERIFY(parser.includeSubDomains());
 
-    list.pop_back();
+    headers.removeAt(headers.size() - 1);
     // Invalid (includeSubDomains twice):
-    list << Header("Strict-Transport-Security", "max-age = 1000 ; includeSubDomains;includeSubDomains");
-    QVERIFY(!parser.parse(list));
+    headers.append("Strict-Transport-Security", "max-age = 1000 ; includeSubDomains;includeSubDomains");
+    QVERIFY(!parser.parse(headers));
     QVERIFY(!parser.includeSubDomains());
     QVERIFY(!parser.expirationDate().isValid());
 
-    list.pop_back();
+    headers.removeAt(headers.size() - 1);
     // Invalid (weird number of seconds):
-    list << Header("Strict-Transport-Security", "max-age=-1000   ; includeSubDomains");
-    QVERIFY(!parser.parse(list));
+    headers.append("Strict-Transport-Security", "max-age=-1000   ; includeSubDomains");
+    QVERIFY(!parser.parse(headers));
     QVERIFY(!parser.includeSubDomains());
     QVERIFY(!parser.expirationDate().isValid());
 
-    list.pop_back();
+    headers.removeAt(headers.size() - 1);
     // Note, directives are case-insensitive + we should ignore unknown directive.
-    list << Header("Strict-Transport-Security", ";max-age=1000 ;includesubdomains;;"
+    headers.append("Strict-Transport-Security", ";max-age=1000 ;includesubdomains;;"
                    "nowsomeunknownheader=\"somevaluewithescapes\\;\"");
-    QVERIFY(parser.parse(list));
+    QVERIFY(parser.parse(headers));
     QVERIFY(parser.includeSubDomains());
     QVERIFY(parser.expirationDate().isValid());
 
-    list.pop_back();
+    headers.removeAt(headers.size() - 1);
     // Check that we know how to unescape max-age:
-    list << Header("Strict-Transport-Security", "max-age=\"1000\"");
-    QVERIFY(parser.parse(list));
+    headers.append("Strict-Transport-Security", "max-age=\"1000\"");
+    QVERIFY(parser.parse(headers));
     QVERIFY(!parser.includeSubDomains());
     QVERIFY(parser.expirationDate().isValid());
 
-    list.pop_back();
+    headers.removeAt(headers.size() - 1);
     // The only STS header, with invalid syntax though, to be ignored:
-    list << Header("Strict-Transport-Security", "max-age; max-age=15768000");
-    QVERIFY(!parser.parse(list));
+    headers.append("Strict-Transport-Security", "max-age; max-age=15768000");
+    QVERIFY(!parser.parse(headers));
     QVERIFY(!parser.includeSubDomains());
     QVERIFY(!parser.expirationDate().isValid());
 
     // Now we check that our parse chosses the first valid STS header and ignores
     // others:
-    list.clear();
-    list << Header("Strict-Transport-Security", "includeSubdomains; max-age=\"hehehe\";");
-    list << Header("Strict-Transport-Security", "max-age=10101");
-    QVERIFY(parser.parse(list));
+    headers.clear();
+    headers.append("Strict-Transport-Security", "includeSubdomains; max-age=\"hehehe\";");
+    headers.append("Strict-Transport-Security", "max-age=10101");
+    QVERIFY(parser.parse(headers));
     QVERIFY(!parser.includeSubDomains());
     QVERIFY(parser.expirationDate().isValid());
 
 
-    list.clear();
-    list << Header("Strict-Transport-Security", "max-age=0");
-    QVERIFY(parser.parse(list));
+    headers.clear();
+    headers.append("Strict-Transport-Security", "max-age=0");
+    QVERIFY(parser.parse(headers));
     QVERIFY(!parser.includeSubDomains());
     QVERIFY(parser.expirationDate() <= QDateTime::currentDateTimeUtc());
 
     // Parsing is case-insensitive:
-    list.pop_back();
-    list << Header("Strict-Transport-Security", "Max-aGE=1000; InclUdesUbdomains");
-    QVERIFY(parser.parse(list));
+    headers.removeAt(headers.size() - 1);
+    headers.append("Strict-Transport-Security", "Max-aGE=1000; InclUdesUbdomains");
+    QVERIFY(parser.parse(headers));
     QVERIFY(parser.includeSubDomains());
     QVERIFY(parser.expirationDate().isValid());
 
     // Grammar of STS header is quite permissive, let's check we can parse
     // some weird but valid header:
-    list.pop_back();
-    list << Header("Strict-Transport-Security", ";;; max-age = 17; ; ; ; ;;; ;;"
+    headers.removeAt(headers.size() - 1);
+    headers.append("Strict-Transport-Security", ";;; max-age = 17; ; ; ; ;;; ;;"
                     ";;; ; includeSubdomains ;;thisIsUnknownDirective;;;;");
-    QVERIFY(parser.parse(list));
+    QVERIFY(parser.parse(headers));
     QVERIFY(parser.includeSubDomains());
     QVERIFY(parser.expirationDate().isValid());
 
-    list.pop_back();
-    list << Header("Strict-Transport-Security", "max-age=1000; includeSubDomains bogon");
-    QVERIFY(!parser.parse(list));
+    headers.removeAt(headers.size() - 1);
+    headers.append("Strict-Transport-Security", "max-age=1000; includeSubDomains bogon");
+    QVERIFY(!parser.parse(headers));
     QVERIFY(!parser.includeSubDomains());
     QVERIFY(!parser.expirationDate().isValid());
 }
diff --git a/tests/auto/network/access/http2/http2srv.cpp b/tests/auto/network/access/http2/http2srv.cpp
index d7c8c2fd8e..f98fed0322 100644
--- a/tests/auto/network/access/http2/http2srv.cpp
+++ b/tests/auto/network/access/http2/http2srv.cpp
@@ -377,16 +377,12 @@ bool Http2Server::verifyProtocolUpgradeRequest()
     bool settingsOk = false;
 
     QHttpNetworkReplyPrivate *firstRequestReader = protocolUpgradeHandler->d_func();
+    const auto headers = firstRequestReader->headers();
 
     // That's how we append them, that's what I expect to find:
-    for (const auto &header : firstRequestReader->headers()) {
-        if (header.first == "Connection")
-            connectionOk = header.second.contains("Upgrade, HTTP2-Settings");
-        else if (header.first == "Upgrade")
-            upgradeOk = header.second.contains("h2c");
-        else if (header.first == "HTTP2-Settings")
-            settingsOk = true;
-    }
+    connectionOk = headers.combinedValue(QHttpHeaders::WellKnownHeader::Connection).contains("Upgrade, HTTP2-Settings");
+    upgradeOk = headers.combinedValue(QHttpHeaders::WellKnownHeader::Upgrade).contains("h2c");
+    settingsOk = headers.contains("HTTP2-Settings");
 
     return connectionOk && upgradeOk && settingsOk;
 }
diff --git a/tests/auto/network/access/qnetworkreply/tst_qnetworkreply.cpp b/tests/auto/network/access/qnetworkreply/tst_qnetworkreply.cpp
index 099cf1b047..8cdd15a5f9 100644
--- a/tests/auto/network/access/qnetworkreply/tst_qnetworkreply.cpp
+++ b/tests/auto/network/access/qnetworkreply/tst_qnetworkreply.cpp
@@ -731,11 +731,11 @@ private:
 
     void parseContentLength()
     {
-        int index = receivedData.indexOf("Content-Length:");
+        int index = receivedData.indexOf("content-length:");
         if (index == -1)
             return;
 
-        index += sizeof("Content-Length:") - 1;
+        index += sizeof("content-length:") - 1;
         const auto end = std::find(receivedData.cbegin() + index, receivedData.cend(), '\r');
         auto num = receivedData.mid(index, std::distance(receivedData.cbegin() + index, end));
         bool ok;
@@ -3451,7 +3451,7 @@ void tst_QNetworkReply::connectToIPv6Address()
     if (!QtNetworkSettings::hasIPv6())
         QSKIP("system doesn't support ipv6!");
 
-    QByteArray httpResponse = QByteArray("HTTP/1.0 200 OK\r\nContent-Length: ");
+    QByteArray httpResponse = QByteArray("HTTP/1.0 200 OK\r\ncontent-length: ");
     httpResponse += QByteArray::number(dataToSend.size());
     httpResponse += "\r\n\r\n";
     httpResponse += dataToSend;
@@ -3466,7 +3466,7 @@ void tst_QNetworkReply::connectToIPv6Address()
     QVERIFY2(waitForFinish(reply) == Success, msgWaitForFinished(reply));
     QByteArray content = reply->readAll();
     //qDebug() << server.receivedData;
-    QByteArray hostinfo = "\r\nHost: " + hostfield + ':' + QByteArray::number(server.serverPort()) + "\r\n";
+    QByteArray hostinfo = "\r\nhost: " + hostfield + ':' + QByteArray::number(server.serverPort()) + "\r\n";
     QVERIFY(server.receivedData.contains(hostinfo));
     QCOMPARE(content, dataToSend);
     QCOMPARE(reply->url(), request.url());
@@ -6275,7 +6275,7 @@ void tst_QNetworkReply::httpProxyCommands()
 
     manager.setProxy(proxy);
     QNetworkRequest request(url);
-    request.setRawHeader("User-Agent", "QNetworkReplyAutoTest/1.0");
+    request.setRawHeader("user-agent", "QNetworkReplyAutoTest/1.0");
     QNetworkReplyPtr reply(manager.get(request));
 
     // wait for the finished signal
@@ -6292,10 +6292,11 @@ void tst_QNetworkReply::httpProxyCommands()
     QCOMPARE(receivedHeader, expectedCommand);
 
     //QTBUG-17223 - make sure the user agent from the request is sent to proxy server even for CONNECT
-    int uapos = proxyServer.receivedData.indexOf("User-Agent");
+    const QByteArray cUserAgent = "user-agent: ";
+    int uapos = proxyServer.receivedData.toLower().indexOf(cUserAgent) + cUserAgent.size();
     int uaend = proxyServer.receivedData.indexOf("\r\n", uapos);
     QByteArray uaheader = proxyServer.receivedData.mid(uapos, uaend - uapos);
-    QCOMPARE(uaheader, QByteArray("User-Agent: QNetworkReplyAutoTest/1.0"));
+    QCOMPARE(uaheader, QByteArray("QNetworkReplyAutoTest/1.0"));
 }
 
 class ProxyChangeHelper : public QObject
@@ -8513,7 +8514,7 @@ void tst_QNetworkReply::httpUserAgent()
 
     QVERIFY(reply->isFinished());
     QCOMPARE(reply->error(), QNetworkReply::NoError);
-    QVERIFY(server.receivedData.contains("\r\nUser-Agent: abcDEFghi\r\n"));
+    QVERIFY(server.receivedData.contains("\r\nuser-agent: abcDEFghi\r\n"));
 }
 
 void tst_QNetworkReply::synchronousAuthenticationCache()
@@ -8533,7 +8534,7 @@ void tst_QNetworkReply::synchronousAuthenticationCache()
                 "Content-Type: text/plain\r\n"
                 "\r\n"
                 "auth";
-            QRegularExpression rx("Authorization: Basic ([^\r\n]*)\r\n");
+            QRegularExpression rx("authorization: Basic ([^\r\n]*)\r\n");
             QRegularExpressionMatch match = rx.match(receivedData);
             if (match.hasMatch()) {
                 if (QByteArray::fromBase64(match.captured(1).toLatin1()) == "login:password") {
@@ -9190,7 +9191,7 @@ void tst_QNetworkReply::ioHttpCookiesDuringRedirect()
     manager.setRedirectPolicy(oldRedirectPolicy);
 
     QVERIFY(waitForFinish(reply) == Success);
-    QVERIFY(target.receivedData.contains("\r\nCookie: hello=world\r\n"));
+    QVERIFY(target.receivedData.contains("\r\ncookie: hello=world\r\n"));
     QVERIFY(validateRedirectedResponseHeaders(reply));
 }
 
@@ -10081,7 +10082,7 @@ void tst_QNetworkReply::contentEncoding()
     QNetworkRequest request(QUrl("http://localhost:" + QString::number(server.serverPort())));
     if (!decompress) {
         // This disables decompression of the received content:
-        request.setRawHeader("Accept-Encoding", QLatin1String("%1").arg(encoding).toLatin1());
+        request.setRawHeader("accept-encoding", QLatin1String("%1").arg(encoding).toLatin1());
         // This disables the zerocopy optimization
         request.setAttribute(QNetworkRequest::MaximumDownloadBufferSizeAttribute, 0);
     }
@@ -10093,7 +10094,7 @@ void tst_QNetworkReply::contentEncoding()
     {
         // Check that we included the content encoding method in our Accept-Encoding header
         const QByteArray &receivedData = server.receivedData;
-        int start = receivedData.indexOf("Accept-Encoding");
+        int start = receivedData.indexOf("accept-encoding");
         QVERIFY(start != -1);
         int end = receivedData.indexOf("\r\n", start);
         QVERIFY(end != -1);
diff --git a/tests/auto/network/access/qrestaccessmanager/httptestserver.cpp b/tests/auto/network/access/qrestaccessmanager/httptestserver.cpp
index 089342ff8b..00995920d5 100644
--- a/tests/auto/network/access/qrestaccessmanager/httptestserver.cpp
+++ b/tests/auto/network/access/qrestaccessmanager/httptestserver.cpp
@@ -67,8 +67,9 @@ void HttpTestServer::handleDataAvailable()
     Q_ASSERT(m_handler);
     Q_ASSERT(state == State::AllDone);
 
-    if (m_request.headers.contains("Host")) {
-        const auto parts = m_request.headers["Host"].split(':');
+    if (auto values = m_request.headers.values(
+                    QHttpHeaders::WellKnownHeader::Host); !values.empty()) {
+        const auto parts = values.first().split(':');
         m_request.url.setHost(parts.at(0));
         if (parts.size() == 2)
             m_request.url.setPort(parts.at(1).toUInt());
@@ -83,8 +84,9 @@ void HttpTestServer::handleDataAvailable()
     responseMessage += QByteArray::number(response.status);
     responseMessage += CRLF;
     // Insert headers if any
-    for (const auto &[name,value] : response.headers.asKeyValueRange()) {
+    for (const auto &[name,value] : response.headers.toListOfPairs()) {
         responseMessage += name;
+        responseMessage += ": ";
         responseMessage += value;
         responseMessage += CRLF;
     }
@@ -236,7 +238,7 @@ bool HttpTestServer::readHeaders(QTcpSocket *socket)
 
                 QByteArray key = fragment.sliced(0, index).trimmed();
                 QByteArray value = fragment.sliced(index + 1).trimmed();
-                m_request.headers.insert(std::move(key), std::move(value));
+                m_request.headers.append(key, value);
                 fragment.clear();
             }
         }
@@ -247,9 +249,10 @@ bool HttpTestServer::readHeaders(QTcpSocket *socket)
 bool HttpTestServer::readBody(QTcpSocket *socket)
 {
     qint64 bytesLeft = 0;
-    if (m_request.headers.contains("Content-Length")) {
+    if (auto values = m_request.headers.values(
+                QHttpHeaders::WellKnownHeader::ContentLength); !values.empty()) {
         bool conversionResult;
-        bytesLeft = m_request.headers["Content-Length"].toInt(&conversionResult);
+        bytesLeft = values.first().toInt(&conversionResult);
         if (!conversionResult)
             return false;
         fragment.resize(bytesLeft);
diff --git a/tests/auto/network/access/qrestaccessmanager/httptestserver_p.h b/tests/auto/network/access/qrestaccessmanager/httptestserver_p.h
index 1498c4bdb7..ead6590a55 100644
--- a/tests/auto/network/access/qrestaccessmanager/httptestserver_p.h
+++ b/tests/auto/network/access/qrestaccessmanager/httptestserver_p.h
@@ -5,6 +5,7 @@
 #define QRESTACCESSSMANAGER_HTTPTESTSERVER_P_H
 
 #include <QtNetwork/qtcpserver.h>
+#include <QtNetwork/qhttpheaders.h>
 
 #include <QtCore/qmap.h>
 #include <QtCore/qurl.h>
@@ -18,7 +19,7 @@ struct HttpData {
     QByteArray method;
     quint16 port = 0;
     QPair<quint8, quint8> version;
-    QMap<QByteArray, QByteArray> headers;
+    QHttpHeaders headers;
 };
 
 struct ResponseControl
diff --git a/tests/auto/network/access/qrestaccessmanager/tst_qrestaccessmanager.cpp b/tests/auto/network/access/qrestaccessmanager/tst_qrestaccessmanager.cpp
index b619f3fcd5..d1018952bd 100644
--- a/tests/auto/network/access/qrestaccessmanager/tst_qrestaccessmanager.cpp
+++ b/tests/auto/network/access/qrestaccessmanager/tst_qrestaccessmanager.cpp
@@ -22,6 +22,8 @@
 using namespace Qt::StringLiterals;
 using namespace std::chrono_literals;
 
+using Header = QHttpHeaders::WellKnownHeader;
+
 class tst_QRestAccessManager : public QObject
 {
     Q_OBJECT
@@ -533,9 +535,9 @@ void tst_QRestAccessManager::authentication()
 
     HttpData serverSideRequest;
     server.setHandler([&](HttpData request, HttpData &response, ResponseControl&) {
-        if (!request.headers.contains("Authorization"_ba)) {
+        if (!request.headers.contains(Header::Authorization)) {
             response.status = 401;
-            response.headers.insert("WWW-Authenticate: "_ba, "Basic realm=\"secret_place\""_ba);
+            response.headers.append(Header::WWWAuthenticate, "Basic realm=\"secret_place\""_ba);
         } else {
             response.status = 200;
         }
@@ -557,7 +559,9 @@ void tst_QRestAccessManager::authentication()
     QTRY_VERIFY(replyFromServer);
     // Server and QRestAM/QNAM exchange req/res twice, but finished() should be emitted just once
     QCOMPARE(finishedCount, 1);
-    QCOMPARE(serverSideRequest.headers["Authorization"_ba], "Basic YV91c2VyOmFfcGFzc3dvcmQ="_ba);
+    const auto resultHeaders = serverSideRequest.headers.values(Header::Authorization);
+    QVERIFY(!resultHeaders.empty());
+    QCOMPARE(resultHeaders.first(), "Basic YV91c2VyOmFfcGFzc3dvcmQ="_ba);
 }
 
 void tst_QRestAccessManager::userInfo()
@@ -576,9 +580,9 @@ void tst_QRestAccessManager::userInfo()
 
     HttpData serverSideRequest;
     server.setHandler([&](HttpData request, HttpData& response, ResponseControl&) {
-        if (!request.headers.contains("Authorization"_ba)) {
+        if (!request.headers.contains(Header::Authorization)) {
             response.status = 401;
-            response.headers.insert("WWW-Authenticate: "_ba, "Basic realm=\"secret_place\""_ba);
+            response.headers.append(Header::WWWAuthenticate,"Basic realm=\"secret_place\""_ba);
         } else {
             response.status = 200;
         }
@@ -589,7 +593,9 @@ void tst_QRestAccessManager::userInfo()
     QTRY_VERIFY(reply.get()->isFinished());
     QVERIFY(reply.get()->isSuccess());
     QCOMPARE(reply.get()->httpStatus(), 200);
-    QCOMPARE(serverSideRequest.headers["Authorization"_ba], "Basic YV91c2VyOmFfcGFzc3dvcmQ="_ba);
+    const auto resultHeaders = serverSideRequest.headers.values(Header::Authorization);
+    QVERIFY(!resultHeaders.empty());
+    QCOMPARE(resultHeaders.first(), "Basic YV91c2VyOmFfcGFzc3dvcmQ="_ba);
 
     // Verify that debug output does not contain password
     QString debugOutput;
@@ -864,33 +870,38 @@ void tst_QRestAccessManager::text()
     // QString from text() should match with the original (UTF-16) QString.
 
     // Successful UTF-8
-    serverSideResponse.headers.insert("Content-Type:"_ba, "text/plain; charset=UTF-8"_ba);
+    serverSideResponse.headers.append(Header::ContentType, "text/plain; charset=UTF-8"_ba);
     serverSideResponse.body = encUTF8(sourceString);
     VERIFY_TEXT_REPLY_OK;
 
     // Successful UTF-16
-    serverSideResponse.headers.insert("Content-Type:"_ba, "text/plain; charset=UTF-16"_ba);
+    serverSideResponse.headers.removeAll(Header::ContentType);
+    serverSideResponse.headers.append(Header::ContentType, "text/plain; charset=UTF-16"_ba);
     serverSideResponse.body = encUTF16(sourceString);
     VERIFY_TEXT_REPLY_OK;
 
     // Successful UTF-16, parameter case insensitivity
-    serverSideResponse.headers.insert("Content-Type:"_ba, "text/plain; chARset=uTf-16"_ba);
+    serverSideResponse.headers.removeAll(Header::ContentType);
+    serverSideResponse.headers.append(Header::ContentType, "text/plain; chARset=uTf-16"_ba);
     serverSideResponse.body = encUTF16(sourceString);
     VERIFY_TEXT_REPLY_OK;
 
     // Successful UTF-32
-    serverSideResponse.headers.insert("Content-Type:"_ba, "text/plain; charset=UTF-32"_ba);
+    serverSideResponse.headers.removeAll(Header::ContentType);
+    serverSideResponse.headers.append(Header::ContentType, "text/plain; charset=UTF-32"_ba);
     serverSideResponse.body = encUTF32(sourceString);
     VERIFY_TEXT_REPLY_OK;
 
     // Successful UTF-32 with spec-wise allowed extra content in the Content-Type header value
-    serverSideResponse.headers.insert("Content-Type:"_ba,
+    serverSideResponse.headers.removeAll(Header::ContentType);
+    serverSideResponse.headers.append(Header::ContentType,
                                       "text/plain; charset = \"UTF-32\";extraparameter=bar"_ba);
     serverSideResponse.body = encUTF32(sourceString);
     VERIFY_TEXT_REPLY_OK;
 
     // Unsuccessful UTF-32, wrong encoding indicated (indicated charset UTF-32 but data is UTF-8)
-    serverSideResponse.headers.insert("Content-Type:"_ba, "text/plain; charset=UTF-32"_ba);
+    serverSideResponse.headers.removeAll(Header::ContentType);
+    serverSideResponse.headers.append(Header::ContentType, "text/plain; charset=UTF-32"_ba);
     serverSideResponse.body = encUTF8(sourceString);
     manager.get(request, this, [&](QRestReply *reply) { replyFromServer = reply; });
     QTRY_VERIFY(replyFromServer);
@@ -900,12 +911,14 @@ void tst_QRestAccessManager::text()
     replyFromServer = nullptr;
 
     // Unsupported encoding
-    serverSideResponse.headers.insert("Content-Type:"_ba, "text/plain; charset=foo"_ba);
+    serverSideResponse.headers.removeAll(Header::ContentType);
+    serverSideResponse.headers.append(Header::ContentType, "text/plain; charset=foo"_ba);
     serverSideResponse.body = encUTF8(sourceString);
     VERIFY_TEXT_REPLY_ERROR("text(): Charset \"foo\" is not supported")
 
     // Broken UTF-8
-    serverSideResponse.headers.insert("Content-Type:"_ba, "text/plain; charset=UTF-8"_ba);
+    serverSideResponse.headers.removeAll(Header::ContentType);
+    serverSideResponse.headers.append(Header::ContentType, "text/plain; charset=UTF-8"_ba);
     serverSideResponse.body = "\xF0\x28\x8C\x28\xA0\xB0\xC0\xD0"; // invalid characters
     VERIFY_TEXT_REPLY_ERROR("text() Decoding error occurred");
 }
@@ -925,7 +938,8 @@ void tst_QRestAccessManager::textStreaming()
     ResponseControl *responseControl = nullptr;
 
     HttpData serverSideResponse; // The response data the server responds with
-    serverSideResponse.headers.insert("Content-Type:"_ba, "text/plain; charset=UTF-8"_ba);
+    serverSideResponse.headers.removeAll(Header::ContentType);
+    serverSideResponse.headers.append(Header::ContentType, "text/plain; charset=UTF-8"_ba);
     serverSideResponse.body = encUTF8(expectedData);
     serverSideResponse.status = 200;
 
@@ -983,7 +997,7 @@ void tst_QRestAccessManager::download()
     ResponseControl *responseControl = nullptr;
     serverSideResponse.status = 200;
     // Set content-length header so that underlying QNAM is able to report bytesTotal correctly
-    serverSideResponse.headers.insert("Content-Length: ",
+    serverSideResponse.headers.append(Header::ContentType,
                                        QString::number(expectedData.size()).toLatin1());
     server.setHandler([&](HttpData, HttpData &response, ResponseControl &control) {
         response = serverSideResponse;
diff --git a/tests/auto/network/kernel/qauthenticator/tst_qauthenticator.cpp b/tests/auto/network/kernel/qauthenticator/tst_qauthenticator.cpp
index 744dabd3da..5dfd652322 100644
--- a/tests/auto/network/kernel/qauthenticator/tst_qauthenticator.cpp
+++ b/tests/auto/network/kernel/qauthenticator/tst_qauthenticator.cpp
@@ -6,6 +6,7 @@
 #include <QTest>
 #include <QtCore/QCoreApplication>
 #include <QtNetwork/QAuthenticator>
+#include <QtNetwork/QHttpHeaders>
 
 #include <private/qauthenticator_p.h>
 
@@ -60,8 +61,8 @@ void tst_QAuthenticator::basicAuth()
     QAuthenticatorPrivate *priv = QAuthenticatorPrivate::getPrivate(auth);
     QCOMPARE(priv->phase, QAuthenticatorPrivate::Start);
 
-    QList<QPair<QByteArray, QByteArray> > headers;
-    headers << qMakePair(QByteArray("WWW-Authenticate"), "Basic " + data.toUtf8());
+    QHttpHeaders headers;
+    headers.append(QByteArray("WWW-Authenticate"), "Basic " + data.toUtf8());
     priv->parseHttpResponse(headers, /*isProxy = */ false, {});
 
     QCOMPARE(auth.realm(), realm);
@@ -103,13 +104,13 @@ void tst_QAuthenticator::ntlmAuth()
     QAuthenticatorPrivate *priv = QAuthenticatorPrivate::getPrivate(auth);
     QCOMPARE(priv->phase, QAuthenticatorPrivate::Start);
 
-    QList<QPair<QByteArray, QByteArray> > headers;
+    QHttpHeaders headers;
 
     // NTLM phase 1: negotiate
     // This phase of NTLM contains no information, other than what we're willing to negotiate
     // Current implementation uses flags:
     //  NTLMSSP_NEGOTIATE_UNICODE | NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_REQUEST_TARGET
-    headers << qMakePair(QByteArrayLiteral("WWW-Authenticate"), QByteArrayLiteral("NTLM"));
+    headers.append(QByteArrayLiteral("WWW-Authenticate"), QByteArrayLiteral("NTLM"));
     priv->parseHttpResponse(headers, /*isProxy = */ false, {});
     if (sso)
         QVERIFY(priv->calculateResponse("GET", "/", u"").startsWith("NTLM "));
@@ -118,7 +119,7 @@ void tst_QAuthenticator::ntlmAuth()
 
     // NTLM phase 2: challenge
     headers.clear();
-    headers << qMakePair(QByteArray("WWW-Authenticate"), "NTLM " + data.toUtf8());
+    headers.append(QByteArray("WWW-Authenticate"), "NTLM " + data.toUtf8());
     priv->parseHttpResponse(headers, /*isProxy = */ false, {});
 
     QEXPECT_FAIL("with-realm", "NTLM authentication code doesn't extract the realm", Continue);
@@ -143,10 +144,10 @@ void tst_QAuthenticator::sha256AndMd5Digest()
     QVERIFY(priv->isMethodSupported("digest")); // sanity check
 
     QCOMPARE(priv->phase, QAuthenticatorPrivate::Start);
-    QList<QPair<QByteArray, QByteArray>> headers;
+    QHttpHeaders headers;
     // Put sha256 first, so that its parsed first...
-    headers.emplace_back("WWW-Authenticate", sha256);
-    headers.emplace_back("WWW-Authenticate", md5);
+    headers.append("WWW-Authenticate", sha256);
+    headers.append("WWW-Authenticate", md5);
     priv->parseHttpResponse(headers, false, QString());
 
     QByteArray response = priv->calculateResponse("GET", "/index", {});