Ensure external value types are initialized before write

Ensure that the logic used when writing to a property having a value
type provided by an external module matches that used for properties
of internal value types.

Change-Id: I925b8b30a211ef813e2a51134411a162b0b146b5
Reviewed-by: Chris Adams <christopher.adams@nokia.com>

3 files changed, 31 insertions, 6 deletions

diff --git a/src/qml/qml/qqmlglobal.cpp b/src/qml/qml/qqmlglobal.cpp
index 1f8de4fae8..c5228d07c3 100644
--- a/src/qml/qml/qqmlglobal.cpp
+++ b/src/qml/qml/qqmlglobal.cpp
@@ -175,6 +175,20 @@ QVariant QQmlValueTypeProvider::createVariantFromString(int type, const QString
     return QVariant();
 }
 
+bool QQmlValueTypeProvider::equalValueType(int type, const void *lhs, const void *rhs)
+{
+    Q_ASSERT(lhs);
+    Q_ASSERT(rhs);
+
+    QQmlValueTypeProvider *p = this;
+    do {
+        if (p->equal(type, lhs, rhs))
+            return true;
+    } while ((p = p->next));
+
+    return false;
+}
+
 bool QQmlValueTypeProvider::storeValueType(int type, const void *src, void *dst, size_t n)
 {
     Q_ASSERT(src);
@@ -226,6 +240,7 @@ bool QQmlValueTypeProvider::createFromString(int, const QString &, void *, size_
 bool QQmlValueTypeProvider::createStringFrom(int, const void *, QString *) { return false; }
 bool QQmlValueTypeProvider::variantFromString(const QString &, QVariant *) { return false; }
 bool QQmlValueTypeProvider::variantFromString(int, const QString &, QVariant *) { return false; }
+bool QQmlValueTypeProvider::equal(int, const void *, const void *) { return false; }
 bool QQmlValueTypeProvider::store(int, const void *, void *, size_t) { return false; }
 bool QQmlValueTypeProvider::read(int, const void *, int, void *) { return false; }
 bool QQmlValueTypeProvider::write(int, const void *, void *, size_t) { return false; }
diff --git a/src/qml/qml/qqmlglobal_p.h b/src/qml/qml/qqmlglobal_p.h
index 04711ae3fc..e5515b60cb 100644
--- a/src/qml/qml/qqmlglobal_p.h
+++ b/src/qml/qml/qqmlglobal_p.h
@@ -158,6 +158,7 @@ public:
     QVariant createVariantFromString(const QString &);
     QVariant createVariantFromString(int, const QString &, bool *);
 
+    bool equalValueType(int, const void *, const void *);
     bool storeValueType(int, const void *, void *, size_t);
     bool readValueType(int, const void *, int, void *);
     bool writeValueType(int, const void *, void *, size_t);
@@ -176,6 +177,7 @@ private:
     virtual bool variantFromString(const QString &, QVariant *);
     virtual bool variantFromString(int, const QString &, QVariant *);
 
+    virtual bool equal(int, const void *, const void *);
     virtual bool store(int, const void *, void *, size_t);
     virtual bool read(int, const void *, int, void *);
     virtual bool write(int, const void *, void *, size_t);
diff --git a/src/qml/qml/qqmlvmemetaobject.cpp b/src/qml/qml/qqmlvmemetaobject.cpp
index b39ca34739..97781617de 100644
--- a/src/qml/qml/qqmlvmemetaobject.cpp
+++ b/src/qml/qml/qqmlvmemetaobject.cpp
@@ -116,6 +116,8 @@ public:
 
     inline void setDataType(int t);
 
+    inline void ensureValueType(int);
+
 private:
     int type;
     void *data[6]; // Large enough to hold all types
@@ -409,6 +411,15 @@ void QQmlVMEVariant::setDataType(int t)
     type = t;
 }
 
+void QQmlVMEVariant::ensureValueType(int t)
+{
+    if (type != t) {
+        cleanup();
+        type = t;
+        QQml_valueTypeProvider()->initValueType(t, dataPtr(), dataSize());
+    }
+}
+
 QQmlVMEMetaObjectEndpoint::QQmlVMEMetaObjectEndpoint()
 {
     callback = &vmecallback;
@@ -645,12 +656,9 @@ int QQmlVMEMetaObject::metaCall(QMetaObject::Call c, int _id, void **a)
                             writeProperty(id, *reinterpret_cast<QVariant *>(a[0]));
                             break;
                         default:
-                            if (! data[id].dataType())
-                                QQml_valueTypeProvider()->initValueType(t, data[id].dataPtr(), data[id].dataSize());
-                            needActivate = QQml_valueTypeProvider()->writeValueType(t, a[0], data[id].dataPtr(), data[id].dataSize());
-                            if (needActivate) {
-                                data[id].setDataType(t);
-                            }
+                            data[id].ensureValueType(t);
+                            needActivate = !QQml_valueTypeProvider()->equalValueType(t, a[0], data[id].dataPtr());
+                            QQml_valueTypeProvider()->writeValueType(t, a[0], data[id].dataPtr(), data[id].dataSize());
                             break;
                         }
                     }