On network redirects, update finalUrl, not url

We want all further imports to be relative to the redirected URL, not
the base one.

Note that this will incorporate any prior URL interceptions into the
final URL if a redirect happens. We don't really want this to happen
because the result of interception is not meant to be the base for
further URL lookup. However, as interception occurs before redirection,
this is unavoidable. Don't use URL interceptors on remote URLs.

Task-number: QTBUG-67882
Change-Id: I6693d14c8af8212dda9954d0bd0293c3c85441ef
(cherry picked from commit cda2680d80)
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

src/qml/qml/qqmltypeloader.cpp

@@ -357,9 +357,8 @@ qreal QQmlDataBlob::progress() const
 
 /*!
 Returns the physical url of the data.  Initially this is the same as
-finalUrl(), but if a network redirect happens while fetching the data, this url
-is updated to reflect the new location. Also, if a URL interceptor is set, it
-will work on this URL and leave finalUrl() alone.
+finalUrl(), but if a URL interceptor is set, it will work on this URL
+and leave finalUrl() alone.
 
 \sa finalUrl()
 */
@@ -380,8 +379,12 @@ QString QQmlDataBlob::urlString() const
 Returns the logical URL to be used for resolving further URLs referred to in
 the code.
 
-This is the blob url passed to the constructor.  If a network redirect
-happens while fetching the data, this url remains the same.
+This is the blob url passed to the constructor. If a URL interceptor rewrites
+the URL, this one stays the same. If a network redirect happens while fetching
+the data, this url is updated to reflect the new location. Therefore, if both
+an interception and a redirection happen, the final url will indirectly
+incorporate the result of the interception, potentially breaking further
+lookups.
 
 \sa url()
 */
@@ -1195,15 +1198,15 @@ void QQmlTypeLoader::networkReplyFinished(QNetworkReply *reply)
         QVariant redirect = reply->attribute(QNetworkRequest::RedirectionTargetAttribute);
         if (redirect.isValid()) {
             QUrl url = reply->url().resolved(redirect.toUrl());
-            blob->m_url = url;
-            blob->m_urlString.clear();
+            blob->m_finalUrl = url;
+            blob->m_finalUrlString.clear();
 
             QNetworkReply *reply = m_thread->networkAccessManager()->get(QNetworkRequest(url));
             QObject *nrp = m_thread->networkReplyProxy();
             QObject::connect(reply, SIGNAL(finished()), nrp, SLOT(finished()));
             m_networkReplies.insert(reply, blob);
 #ifdef DATABLOB_DEBUG
-            qWarning("QQmlDataBlob: redirected to %s", qPrintable(blob->urlString()));
+            qWarning("QQmlDataBlob: redirected to %s", qPrintable(blob->finalUrlString()));
 #endif
             return;
         }

tests/auto/qml/qqmltypeloader/data/Base.qml

@@ -0,0 +1,3 @@
+import QtQml 2.0
+
+QtObject {}

tests/auto/qml/qqmltypeloader/data/Load.qml

@@ -0,0 +1,11 @@
+import QtQuick 2.0
+
+Item {
+    property int xy: loader.xy
+    Loader {
+        id: loader
+        asynchronous: true
+        source: 'Base.qml'
+        property int xy: item.xy
+    }
+}

tests/auto/qml/qqmltypeloader/data/redirected/Imported.qml

@@ -0,0 +1,5 @@
+import QtQml 2.0
+
+QtObject {
+    property int xy: 323232
+}

tests/auto/qml/qqmltypeloader/data/redirected/Redirected.qml

@@ -0,0 +1,5 @@
+import QtQml 2.0
+
+Imported {
+
+}

tests/auto/qml/qqmltypeloader/data/redirected/qmldir

@@ -0,0 +1 @@
+Imported 1.0 Imported.qml

tests/auto/qml/qqmltypeloader/tst_qqmltypeloader.cpp

@@ -33,6 +33,7 @@
 #include <QtQuick/qquickitem.h>
 #include <QtQml/private/qqmlengine_p.h>
 #include <QtQml/private/qqmltypeloader_p.h>
+#include "../../shared/testhttpserver.h"
 #include "../../shared/util.h"
 
 class tst_QQMLTypeLoader : public QQmlDataTest
@@ -48,6 +49,7 @@ private slots:
     void keepSingleton();
     void keepRegistrations();
     void intercept();
+    void redirect();
 };
 
 void tst_QQMLTypeLoader::testLoadComplete()
@@ -410,6 +412,22 @@ void tst_QQMLTypeLoader::intercept()
     QVERIFY(factory.loadedFiles.contains(QLatin1String(QT_TESTCASE_BUILDDIR) + "/Slow/qmldir"));
 }
 
+void tst_QQMLTypeLoader::redirect()
+{
+    TestHTTPServer server;
+    QVERIFY2(server.listen(), qPrintable(server.errorString()));
+    QVERIFY(server.serveDirectory(dataDirectory()));
+    server.addRedirect("Base.qml", server.urlString("/redirected/Redirected.qml"));
+
+    QQmlEngine engine;
+    QQmlComponent component(&engine);
+    component.loadUrl(server.urlString("/Load.qml"), QQmlComponent::Asynchronous);
+    QTRY_VERIFY2(component.isReady(), qPrintable(component.errorString()));
+
+    QObject *object = component.create();
+    QTRY_COMPARE(object->property("xy").toInt(), 323232);
+}
+
 QTEST_MAIN(tst_QQMLTypeLoader)
 
 #include "tst_qqmltypeloader.moc"

tests/auto/qml/qqmltypeloader/tst_qqmltypeloader.pro

@@ -3,7 +3,12 @@ TARGET = tst_qqmltypeloader
 QT += qml testlib qml-private quick
 macx:CONFIG -= app_bundle
 
-SOURCES += tst_qqmltypeloader.cpp
+SOURCES += \
+    tst_qqmltypeloader.cpp \
+    ../../shared/testhttpserver.cpp
+
+HEADERS += \
+    ../../shared/testhttpserver.h
 
 include (../../shared/util.pri)