Use QUrl::isLocalFile and fix the scheme checking in local URLs.

RFC 3986 requires that schemes be compared case-insensitively, so
"QRC:/" is allowed for Qt resources.

Also document the use of file engines and search paths.

Reviewed-by: Markus Goetz

3 files changed, 19 insertions, 9 deletions

diff --git a/src/network/access/qnetworkaccessfilebackend.cpp b/src/network/access/qnetworkaccessfilebackend.cpp
index 4560153..710c258 100644
--- a/src/network/access/qnetworkaccessfilebackend.cpp
+++ b/src/network/access/qnetworkaccessfilebackend.cpp
@@ -65,10 +65,15 @@ QNetworkAccessFileBackendFactory::create(QNetworkAccessManager::Operation op,
     }
 
     QUrl url = request.url();
-    if (url.scheme() == QLatin1String("qrc") || !url.toLocalFile().isEmpty())
+    if (url.scheme().compare(QLatin1String("qrc"), Qt::CaseInsensitive) == 0 || url.isLocalFile()) {
         return new QNetworkAccessFileBackend;
-    else if (!url.isEmpty() && url.authority().isEmpty()) {
-        // check if QFile could, in theory, open this URL
+    } else if (!url.scheme().isEmpty() && url.authority().isEmpty()) {
+        // check if QFile could, in theory, open this URL via the file engines
+        // it has to be in the format:
+        //    prefix:path/to/file
+        // or prefix:/path/to/file
+        //
+        // this construct here must match the one below in open()
         QFileInfo fi(url.toString(QUrl::RemoveAuthority | QUrl::RemoveFragment | QUrl::RemoveQuery));
         if (fi.exists() || (op == QNetworkAccessManager::PutOperation && fi.dir().exists()))
             return new QNetworkAccessFileBackend;
diff --git a/src/network/access/qnetworkaccessmanager.cpp b/src/network/access/qnetworkaccessmanager.cpp
index 1c7661d..10fdc6f 100644
--- a/src/network/access/qnetworkaccessmanager.cpp
+++ b/src/network/access/qnetworkaccessmanager.cpp
@@ -907,21 +907,20 @@ QNetworkReply *QNetworkAccessManager::createRequest(QNetworkAccessManager::Opera
 {
     Q_D(QNetworkAccessManager);
 
+    bool isLocalFile = req.url().isLocalFile();
+
     // fast path for GET on file:// URLs
-    // Also if the scheme is empty we consider it a file.
     // The QNetworkAccessFileBackend will right now only be used
     // for PUT or qrc://
     if ((op == QNetworkAccessManager::GetOperation || op == QNetworkAccessManager::HeadOperation)
-         && (req.url().scheme() == QLatin1String("file")
-             || req.url().scheme().isEmpty())) {
+         && isLocalFile) {
         return new QFileNetworkReply(this, req, op);
     }
 
 #ifndef QT_NO_BEARERMANAGEMENT
     // Return a disabled network reply if network access is disabled.
     // Except if the scheme is empty or file://.
-    if (!d->networkAccessible && !(req.url().scheme() == QLatin1String("file") ||
-                                      req.url().scheme().isEmpty())) {
+    if (!d->networkAccessible && !isLocalFile) {
         return new QDisabledNetworkReply(this, req, op);
     }
 
@@ -963,7 +962,7 @@ QNetworkReply *QNetworkAccessManager::createRequest(QNetworkAccessManager::Opera
     QUrl url = request.url();
     QNetworkReplyImpl *reply = new QNetworkReplyImpl(this);
 #ifndef QT_NO_BEARERMANAGEMENT
-    if (req.url().scheme() != QLatin1String("file") && !req.url().scheme().isEmpty()) {
+    if (!isLocalFile) {
         connect(this, SIGNAL(networkSessionConnected()),
                 reply, SLOT(_q_networkSessionConnected()));
     }
diff --git a/tests/auto/qnetworkreply/tst_qnetworkreply.cpp b/tests/auto/qnetworkreply/tst_qnetworkreply.cpp
index 9d942bf..c4d458f 100644
--- a/tests/auto/qnetworkreply/tst_qnetworkreply.cpp
+++ b/tests/auto/qnetworkreply/tst_qnetworkreply.cpp
@@ -1166,6 +1166,12 @@ void tst_QNetworkReply::getErrors_data()
     QTest::addColumn<int>("httpStatusCode");
     QTest::addColumn<bool>("dataIsEmpty");
 
+    // empties
+    QTest::newRow("empty-url") << QString() << int(QNetworkReply::ProtocolUnknownError) << 0 << true;
+    QTest::newRow("empty-scheme-host") << SRCDIR "/rfc3252.txt" << int(QNetworkReply::ProtocolUnknownError) << 0 << true;
+    QTest::newRow("empty-scheme") << "//" + QtNetworkSettings::winServerName() + "/testshare/test.pri"
+            << int(QNetworkReply::ProtocolUnknownError) << 0 << true;
+
     // file: errors
     QTest::newRow("file-host") << "file://this-host-doesnt-exist.troll.no/foo.txt"
 #if !defined Q_OS_WIN