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

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

Amends commit 3ea55bf398412d373daab9c92b1498f45de70e96.

Pick-to: 6.2
Fixes: QTBUG-121710
Change-Id: I7f856140286bba9d49b7ed1abfdf398a65fb1962
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
(cherry picked from commit f3bcbfd6a50fb7e74f4ff6714d3b3066fa74e253)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
(cherry picked from commit ec692b22e7b45bef016280a15c8205969e808e12)
(cherry picked from commit 3a8028b393f6b5345f5653d81f49efa31021fae1)

7 files changed, 37 insertions, 3 deletions

diff --git a/src/qml/common/qv4compileddata_p.h b/src/qml/common/qv4compileddata_p.h
index 47b64a6213..8dfb5f7fd6 100644
--- a/src/qml/common/qv4compileddata_p.h
+++ b/src/qml/common/qv4compileddata_p.h
@@ -670,6 +670,8 @@ struct Binding
     }
     bool evaluatesToString() const { return type() == Type_String || isTranslationBinding(); }
 
+    bool isNumberBinding() const { return type() == Type_Number; }
+
     bool valueAsBoolean() const
     {
         if (type() == Type_Boolean)
diff --git a/src/qml/qml/qqmlobjectcreator.cpp b/src/qml/qml/qqmlobjectcreator.cpp
index 4b60dbe655..6b8d57807f 100644
--- a/src/qml/qml/qqmlobjectcreator.cpp
+++ b/src/qml/qml/qqmlobjectcreator.cpp
@@ -313,7 +313,10 @@ void QQmlObjectCreator::setPropertyValue(const QQmlPropertyData *property, const
     QMetaType propertyType = property->propType();
 
     if (property->isEnum()) {
-        if (binding->hasFlag(QV4::CompiledData::Binding::IsResolvedEnum)) {
+        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 = QMetaType::fromType<int>();
         } else {
             // ### This should be resolved earlier at compile time and the binding value should be changed accordingly.
diff --git a/src/qml/qml/qqmlpropertycachecreator_p.h b/src/qml/qml/qqmlpropertycachecreator_p.h
index 71f1cd7f0b..162e8d01a6 100644
--- a/src/qml/qml/qqmlpropertycachecreator_p.h
+++ b/src/qml/qml/qqmlpropertycachecreator_p.h
@@ -864,10 +864,10 @@ inline QQmlError QQmlPropertyCacheAliasCreator<ObjectContainer>::propertyDataFor
             resettable = property->isResettable();
             bindable = property->isBindable();
 
-            // Copy type flags
-            propertyFlags->copyPropertyTypeFlags(property->flags());
             if (property->isVarProperty())
                 propertyFlags->type = QQmlPropertyData::Flags::QVariantType;
+            else
+                propertyFlags->copyPropertyTypeFlags(property->flags());
         };
 
         // for deep aliases, valueTypeIndex is always set
diff --git a/src/qml/qml/qqmlpropertyvalidator.cpp b/src/qml/qml/qqmlpropertyvalidator.cpp
index ead8f78f33..ad8cb5a617 100644
--- a/src/qml/qml/qqmlpropertyvalidator.cpp
+++ b/src/qml/qml/qqmlpropertyvalidator.cpp
@@ -364,6 +364,11 @@ 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;
diff --git a/tests/auto/qml/qqmllanguage/data/AliasHolder.qml b/tests/auto/qml/qqmllanguage/data/AliasHolder.qml
new file mode 100644
index 0000000000..42aed6ed26
--- /dev/null
+++ b/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 }
+}
diff --git a/tests/auto/qml/qqmllanguage/data/aliasWriter.qml b/tests/auto/qml/qqmllanguage/data/aliasWriter.qml
new file mode 100644
index 0000000000..4001c2af34
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/aliasWriter.qml
@@ -0,0 +1,5 @@
+import QtQml
+
+AliasHolder {
+    strokeStyle: 1
+}
diff --git a/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp b/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
index 1a19d19b3b..5b0a4346a5 100644
--- a/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
+++ b/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
@@ -424,6 +424,8 @@ private slots:
     void objectInQmlListAndGc();
     void deepAliasOnICOrReadonly();
 
+    void writeNumberToEnumAlias();
+
 private:
     QQmlEngine engine;
     QStringList defaultImportPathList;
@@ -8143,6 +8145,17 @@ void tst_qqmllanguage::deepAliasOnICOrReadonly()
                     "Invalid property assignment: \"readonlyRectX\" is a read-only property")));
 }
 
+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"