Add a checksum to QQmlPropertyCache

By running an md5 hash over the meta-object data and string tables this will
allow us to detect changes to meta-objects and invalidate QML disk caches.

Change-Id: I15b92de4cdf0cb525281b86e1c7b8ba0b11347a0
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>

1 files changed, 38 insertions, 0 deletions

diff --git a/tests/auto/qml/qqmlpropertycache/tst_qqmlpropertycache.cpp b/tests/auto/qml/qqmlpropertycache/tst_qqmlpropertycache.cpp
index acc68befb5..2916d8455c 100644
--- a/tests/auto/qml/qqmlpropertycache/tst_qqmlpropertycache.cpp
+++ b/tests/auto/qml/qqmlpropertycache/tst_qqmlpropertycache.cpp
@@ -31,6 +31,7 @@
 #include <QtQml/qqmlengine.h>
 #include <private/qv8engine_p.h>
 #include <private/qmetaobjectbuilder_p.h>
+#include <QCryptographicHash>
 #include "../../shared/util.h"
 
 class tst_qqmlpropertycache : public QObject
@@ -48,6 +49,7 @@ private slots:
     void signalHandlersDerived();
     void metaObjectSize_data();
     void metaObjectSize();
+    void metaObjectChecksum();
 
 private:
     QQmlEngine engine;
@@ -361,4 +363,40 @@ void tst_qqmlpropertycache::metaObjectSize()
     QCOMPARE(stringDataSize, expectedStringCount);
 }
 
+void tst_qqmlpropertycache::metaObjectChecksum()
+{
+    QMetaObjectBuilder builder;
+    builder.setClassName("Test");
+    builder.addClassInfo("foo", "bar");
+
+    QCryptographicHash hash(QCryptographicHash::Md5);
+
+    QScopedPointer<QMetaObject, QScopedPointerPodDeleter> mo(builder.toMetaObject());
+    QVERIFY(!mo.isNull());
+
+    QVERIFY(QQmlPropertyCache::addToHash(hash, *mo.data()));
+    QByteArray initialHash = hash.result();
+    QVERIFY(!initialHash.isEmpty());
+    hash.reset();
+
+    {
+        QVERIFY(QQmlPropertyCache::addToHash(hash, *mo.data()));
+        QByteArray nextHash = hash.result();
+        QVERIFY(!nextHash.isEmpty());
+        hash.reset();
+        QCOMPARE(initialHash, nextHash);
+    }
+
+    builder.addProperty("testProperty", "int", -1);
+
+    mo.reset(builder.toMetaObject());
+    {
+        QVERIFY(QQmlPropertyCache::addToHash(hash, *mo.data()));
+        QByteArray nextHash = hash.result();
+        QVERIFY(!nextHash.isEmpty());
+        hash.reset();
+        QVERIFY(initialHash != nextHash);
+    }
+}
+
 QTEST_MAIN(tst_qqmlpropertycache)