Cleanup mess in public type ids.

There is no reason to keep two separated core types sets. It
couldn't be fixed before Qt5 because of binary compatibility promise.

This patch merges QMetaType core types with ext core types.

This "simple" operation consists of:
- QDataStream version was incremented, because type ids are
saved in QVariant's data stream.
- QMetaType LastExtCoreType and FirstExtCoreType were replaced by
LastCoreType, FirstCoreType and new QMetaType::HighestInternalId.
- New tests checking QVariant data stream for Qt4 and for Qt5 versions
were added.

Change-Id: I02dd74d29317365c297a789a4eb7c9c5edc3b231
Reviewed-by: João Abecasis <joao.abecasis@nokia.com>

4 files changed, 71 insertions, 40 deletions

diff --git a/src/corelib/kernel/qmetatype.cpp b/src/corelib/kernel/qmetatype.cpp
index 1c106f4f36..e5fd8a5d24 100644
--- a/src/corelib/kernel/qmetatype.cpp
+++ b/src/corelib/kernel/qmetatype.cpp
@@ -228,14 +228,13 @@ template<> struct TypeDefiniton<QRegExp> { static const bool IsAvailable = false
 
     \value User  Base value for user types
 
-    \omitvalue FirstCoreExtType
     \omitvalue FirstGuiType
     \omitvalue FirstWidgetsType
-    \omitvalue LastCoreExtType
     \omitvalue LastCoreType
     \omitvalue LastGuiType
     \omitvalue LastWidgetsType
     \omitvalue QReal
+    \omitvalue HighestInternalId
 
     Additional types can be registered using Q_DECLARE_METATYPE().
 
@@ -362,10 +361,10 @@ const char *QMetaType::typeName(int type)
     // In theory it can be filled during compilation time, but for some reason template code
     // that is able to do it causes GCC 4.6 to generate additional 3K of executable code. Probably
     // it is not worth of it.
-    static const char *namesCache[QMetaType::LastCoreExtType + 1];
+    static const char *namesCache[QMetaType::HighestInternalId + 1];
 
     const char *result;
-    if (type <= QMetaType::LastCoreExtType && ((result = namesCache[type])))
+    if (type <= QMetaType::HighestInternalId && ((result = namesCache[type])))
         return result;
 
 #define QT_METATYPE_TYPEID_TYPENAME_CONVERTER(MetaTypeName, TypeId, RealName) \
@@ -388,7 +387,7 @@ const char *QMetaType::typeName(int type)
     }
 #undef QT_METATYPE_TYPEID_TYPENAME_CONVERTER
 
-    Q_ASSERT(type <= QMetaType::LastCoreExtType);
+    Q_ASSERT(type <= QMetaType::HighestInternalId);
     namesCache[type] = result;
     return result;
 }
diff --git a/src/corelib/kernel/qmetatype.h b/src/corelib/kernel/qmetatype.h
index 5a55ca9bd7..bbe482428f 100644
--- a/src/corelib/kernel/qmetatype.h
+++ b/src/corelib/kernel/qmetatype.h
@@ -65,16 +65,16 @@ QT_BEGIN_NAMESPACE
     F(LongLong, 4, qlonglong) \
     F(ULongLong, 5, qulonglong) \
     F(Double, 6, double) \
-    F(Long, 129, long) \
-    F(Short, 130, short) \
-    F(Char, 131, char) \
-    F(ULong, 132, ulong) \
-    F(UShort, 133, ushort) \
-    F(UChar, 134, uchar) \
-    F(Float, 135, float) \
+    F(Long, 32, long) \
+    F(Short, 33, short) \
+    F(Char, 34, char) \
+    F(ULong, 35, ulong) \
+    F(UShort, 36, ushort) \
+    F(UChar, 37, uchar) \
+    F(Float, 38, float) \
 
 #define QT_FOR_EACH_STATIC_PRIMITIVE_POINTER(F)\
-    F(VoidStar, 128, void*) \
+    F(VoidStar, 31, void*) \
 
 #define QT_FOR_EACH_STATIC_CORE_CLASS(F)\
     F(QChar, 7, QChar) \
@@ -98,12 +98,12 @@ QT_BEGIN_NAMESPACE
     F(QRegExp, 27, QRegExp) \
     F(QEasingCurve, 29, QEasingCurve) \
     F(QUuid, 30, QUuid) \
-    F(QModelIndex, 31, QModelIndex) \
-    F(QVariant, 138, QVariant) \
+    F(QVariant, 41, QVariant) \
+    F(QModelIndex, 42, QModelIndex) \
 
 #define QT_FOR_EACH_STATIC_CORE_POINTER(F)\
-    F(QObjectStar, 136, QObject*) \
-    F(QWidgetStar, 137, QWidget*) \
+    F(QObjectStar, 39, QObject*) \
+    F(QWidgetStar, 40, QWidget*) \
 
 #define QT_FOR_EACH_STATIC_CORE_TEMPLATE(F)\
     F(QVariantMap, 8, QVariantMap) \
@@ -188,8 +188,7 @@ public:
         LastGuiType = QPolygonF,
         FirstWidgetsType = QIcon,
         LastWidgetsType = QSizePolicy,
-        FirstCoreExtType = VoidStar,
-        LastCoreExtType = QVariant,
+        HighestInternalId = LastWidgetsType,
 
 // This logic must match the one in qglobal.h
 #if defined(QT_COORD_TYPE)
diff --git a/src/corelib/kernel/qmetatype_p.h b/src/corelib/kernel/qmetatype_p.h
index e7a7ed8019..45768bb3b9 100644
--- a/src/corelib/kernel/qmetatype_p.h
+++ b/src/corelib/kernel/qmetatype_p.h
@@ -68,8 +68,6 @@ static inline int moduleForType(const int typeId)
         return Gui;
     if (typeId <= QMetaType::LastWidgetsType)
         return Widgets;
-    if (typeId <= QMetaType::LastCoreExtType)
-        return Core;
     return Unknown;
 }
 }
diff --git a/src/corelib/kernel/qvariant.cpp b/src/corelib/kernel/qvariant.cpp
index e0d1114622..c14e6ffd17 100644
--- a/src/corelib/kernel/qvariant.cpp
+++ b/src/corelib/kernel/qvariant.cpp
@@ -1625,7 +1625,7 @@ QVariant::Type QVariant::nameToType(const char *name)
 
 #ifndef QT_NO_DATASTREAM
 enum { MapFromThreeCount = 36 };
-static const ushort map_from_three[MapFromThreeCount] =
+static const ushort mapIdFromQt3ToCurrent[MapFromThreeCount] =
 {
     QVariant::Invalid,
     QVariant::Map,
@@ -1675,26 +1675,45 @@ void QVariant::load(QDataStream &s)
 {
     clear();
 
-    quint32 u;
-    s >> u;
+    quint32 typeId;
+    s >> typeId;
     if (s.version() < QDataStream::Qt_4_0) {
-        if (u >= MapFromThreeCount)
+        if (typeId >= MapFromThreeCount)
             return;
-        u = map_from_three[u];
+        typeId = mapIdFromQt3ToCurrent[typeId];
+    } else if (s.version() < QDataStream::Qt_5_0) {
+        if (typeId >= 128 && typeId != QVariant::UserType) {
+            // In Qt4 id == 128 was FirstExtCoreType. In Qt5 ExtCoreTypes set was merged to CoreTypes
+            // by moving all ids down by 97.
+            typeId -= 97;
+        } else if (typeId == 69 /* QIcon */) {
+            // In Qt5 after modularization project this types where moved to a separate module (and ids were downgraded)
+            typeId = QMetaType::QIcon;
+        } else if (typeId == 75 /* QSizePolicy */) {
+            typeId = QMetaType::QSizePolicy;
+        } else if (typeId >= 70) {
+            // and as a result this types recieved lower ids too
+            if (typeId <= 74) { // QImage QPolygon QRegion QBitmap QCursor
+                typeId -=1;
+            } else if (typeId <= 86) { // QKeySequence QPen QTextLength QTextFormat QMatrix QTransform QMatrix4x4 QVector2D QVector3D QVector4D QQuaternion
+                typeId -=2;
+            }
+        }
     }
+
     qint8 is_null = false;
     if (s.version() >= QDataStream::Qt_4_2)
         s >> is_null;
-    if (u == QVariant::UserType) {
+    if (typeId == QVariant::UserType) {
         QByteArray name;
         s >> name;
-        u = QMetaType::type(name);
-        if (!u) {
+        typeId = QMetaType::type(name);
+        if (!typeId) {
             s.setStatus(QDataStream::ReadCorruptData);
             return;
         }
     }
-    create(static_cast<int>(u), 0);
+    create(static_cast<int>(typeId), 0);
     d.is_null = is_null;
 
     if (!isValid()) {
@@ -1720,12 +1739,12 @@ void QVariant::load(QDataStream &s)
 */
 void QVariant::save(QDataStream &s) const
 {
-    quint32 tp = type();
+    quint32 typeId = type();
     if (s.version() < QDataStream::Qt_4_0) {
         int i;
         for (i = MapFromThreeCount - 1; i >= 0; i--) {
-            if (map_from_three[i] == tp) {
-                tp = i;
+            if (mapIdFromQt3ToCurrent[i] == typeId) {
+                typeId = i;
                 break;
             }
         }
@@ -1733,11 +1752,29 @@ void QVariant::save(QDataStream &s) const
             s << QVariant();
             return;
         }
+    } else if (s.version() < QDataStream::Qt_5_0) {
+        if (typeId >= 128 - 97 && typeId <= LastCoreType) {
+            // In Qt4 id == 128 was FirstExtCoreType. In Qt5 ExtCoreTypes set was merged to CoreTypes
+            // by moving all ids down by 97.
+            typeId += 97;
+        } else if (typeId == QMetaType::QIcon) {
+            // In Qt5 after modularization project this types where moved to a separate module (and ids were downgraded)
+            typeId = 69;
+        } else if (typeId == QMetaType::QSizePolicy) {
+            typeId = 75;
+        } else if (typeId >= QMetaType::QImage) {
+            // and as a result this types recieved lower ids too
+            if (typeId <= QMetaType::QCursor) {
+                typeId +=1;
+            } else if (typeId <= QMetaType::QQuaternion) {
+                typeId +=2;
+            }
+        }
     }
-    s << tp;
+    s << typeId;
     if (s.version() >= QDataStream::Qt_4_2)
         s << qint8(d.is_null);
-    if (tp == QVariant::UserType) {
+    if (typeId == QVariant::UserType) {
         s << QMetaType::typeName(userType());
     }
 
@@ -2411,17 +2448,15 @@ static const quint32 qCanConvertMatrix[QVariant::LastCoreType + 1] =
 */
 bool QVariant::canConvert(Type t) const
 {
-    //we can treat floats as double
-    //the reason for not doing it the "proper" way is that QMetaType::Float's value is 135,
-    //which can't be handled by qCanConvertMatrix
-    //In addition QVariant::Type doesn't have a Float value, so we're using QMetaType::Float
+    // TODO Reimplement this function, currently it works but it is a historical mess.
     const uint currentType = ((d.type == QMetaType::Float) ? QVariant::Double : d.type);
     if (uint(t) == uint(QMetaType::Float)) t = QVariant::Double;
 
     if (currentType == uint(t))
         return true;
 
-    if (currentType > QVariant::LastCoreType || t > QVariant::LastCoreType) {
+    // FIXME It should be LastCoreType intead of Uuid
+    if (currentType > QVariant::Uuid || t > QVariant::Uuid) {
         switch (uint(t)) {
         case QVariant::Int:
             return currentType == QVariant::KeySequence