QtQml: Re-allow assigning of raw numbers to enum property aliases

This used to work and we cannot just take it away.

Amends commit 3ea55bf.

Pick-to: 6.7 6.6 6.5 6.2
Fixes: QTBUG-121710
Change-Id: I7f856140286bba9d49b7ed1abfdf398a65fb1962
Reviewed-by: Fabian Kosmale <[email protected]>

Author: Ulf Hermann

src/qml/common/qv4compileddata_p.h

@@ -707,6 +707,8 @@ struct Binding
     }
     bool evaluatesToString() const { return type() == Type_String || isTranslationBinding(); }
 
+    bool isNumberBinding() const { return type() == Type_Number; }
+
     bool valueAsBoolean() const
     {
         if (type() == Type_Boolean)

src/qml/qml/qqmlobjectcreator.cpp

@@ -315,8 +315,11 @@ void QQmlObjectCreator::setPropertyValue(const QQmlPropertyData *property, const
     QMetaType propertyType = property->propType();
 
     if (property->isEnum()) {
-        if (binding->hasFlag(QV4::CompiledData::Binding::IsResolvedEnum)) {
-            propertyType = QMetaType::fromType<int>();
+        if (binding->hasFlag(QV4::CompiledData::Binding::IsResolvedEnum) ||
+                // TODO: For historical reasons you can assign any number to an enum property alias
+                //       This can be fixed with an opt-out mechanism, for example a pragma.
+                (property->isAlias() && binding->isNumberBinding())) {
+            propertyType = property->propType().underlyingType();
         } else {
             // ### This should be resolved earlier at compile time and the binding value should be changed accordingly.
             QVariant value = compilationUnit->bindingValueAsString(binding);

src/qml/qml/qqmlpropertycachecreator_p.h

@@ -905,10 +905,10 @@ inline QQmlError QQmlPropertyCacheAliasCreator<ObjectContainer>::propertyDataFor
             resettable = property->isResettable();
             bindable = property->isBindable();
 
-            // Copy type flags
-            propertyFlags->copyPropertyTypeFlags(property->flags());
             if (property->isVarProperty())
                 propertyFlags->setType(QQmlPropertyData::Flags::QVariantType);
+            else
+                propertyFlags->copyPropertyTypeFlags(property->flags());
         };
 
         // for deep aliases, valueTypeIndex is always set

src/qml/qml/qqmlpropertyvalidator.cpp

@@ -374,6 +374,11 @@ QQmlError QQmlPropertyValidator::validateLiteralBinding(
         if (binding->hasFlag(QV4::CompiledData::Binding::IsResolvedEnum))
             return noError;
 
+        // TODO: For historical reasons you can assign any number to an enum property alias
+        //       This can be fixed with an opt-out mechanism, for example a pragma.
+        if (property->isAlias() && binding->isNumberBinding())
+            return noError;
+
         QString value = compilationUnit->bindingValueAsString(binding);
         QMetaProperty p = propertyCache->firstCppMetaObject()->property(property->coreIndex());
         bool ok;

tests/auto/qml/qqmllanguage/data/AliasHolder.qml

@@ -0,0 +1,6 @@
+import QtQml
+
+QtObject {
+    property alias strokeStyle: path.restoreMode
+    property Binding p: Binding { id: path }
+}

tests/auto/qml/qqmllanguage/data/aliasWriter.qml

@@ -0,0 +1,5 @@
+import QtQml
+
+AliasHolder {
+    strokeStyle: 1
+}

tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp

@@ -442,6 +442,8 @@ private slots:
 
     void ambiguousComponents();
 
+    void writeNumberToEnumAlias();
+
 private:
     QQmlEngine engine;
     QStringList defaultImportPathList;
@@ -8501,6 +8503,17 @@ void tst_qqmllanguage::ambiguousComponents()
     QVERIFY(isInstanceOf);
 }
 
+void tst_qqmllanguage::writeNumberToEnumAlias()
+{
+    QQmlEngine engine;
+    QQmlComponent c(&engine, testFileUrl("aliasWriter.qml"));
+    QVERIFY2(c.isReady(), qPrintable(c.errorString()));
+    QScopedPointer<QObject> o(c.create());
+    QVERIFY(!o.isNull());
+
+    QCOMPARE(o->property("strokeStyle").toInt(), 1);
+}
+
 QTEST_MAIN(tst_qqmllanguage)
 
 #include "tst_qqmllanguage.moc"