Added stream version into network cache file format

At the moment, there is no stream information in the cache file. This
can lead to a problem when current stream version differs from version
cache file written with.

As an example, if file written with Qt 5.1.1, QTimeDate in the metadata
stored as 13-bytes value, but Qt 5.2 and later can read additional 4
bytes which breaks following data, leading to network request just hangs
forever.

Adding stream version fixes this problem.

As cache format changed, cache version bumped.

Task-number: QTBUG-36219
Change-Id: I467d8c9fda82bcf9302192f51e7a00d2f6a9ff66
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@digia.com>

1 files changed, 9 insertions, 1 deletions

diff --git a/src/network/access/qnetworkdiskcache.cpp b/src/network/access/qnetworkdiskcache.cpp
index a1cbd9364e..86a3b20a9c 100644
--- a/src/network/access/qnetworkdiskcache.cpp
+++ b/src/network/access/qnetworkdiskcache.cpp
@@ -56,7 +56,7 @@
 
 #define CACHE_POSTFIX QLatin1String(".d")
 #define PREPARED_SLASH QLatin1String("prepared/")
-#define CACHE_VERSION 7
+#define CACHE_VERSION 8
 #define DATA_DIR QLatin1String("data")
 
 #define MAX_COMPRESSION_SIZE (1024 * 1024 * 3)
@@ -686,6 +686,7 @@ void QCacheItem::writeHeader(QFile *device) const
 
     out << qint32(CacheMagic);
     out << qint32(CurrentCacheVersion);
+    out << static_cast<qint32>(out.version());
     out << metaData;
     bool compressed = canCompress();
     out << compressed;
@@ -719,6 +720,13 @@ bool QCacheItem::read(QFile *device, bool readData)
     if (v != CurrentCacheVersion)
         return false;
 
+    qint32 streamVersion;
+    in >> streamVersion;
+    // Default stream version is also the highest we can handle
+    if (streamVersion > in.version())
+        return false;
+    in.setVersion(streamVersion);
+
     bool compressed;
     QByteArray dataBA;
     in >> metaData;