Fix QQmlEngine::retranslate() with PropertyChanges

When changing the language, we need to re-apply the state of items and
re-run the translations if present.

Task-number: QTBUG-66541
Change-Id: I83a542af033990ef9a0f92801c5f52d3a5ec722c
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

4 files changed, 36 insertions, 11 deletions

diff --git a/src/quick/util/qquickpropertychanges.cpp b/src/quick/util/qquickpropertychanges.cpp
index f79dbf35a0..a3a598621f 100644
--- a/src/quick/util/qquickpropertychanges.cpp
+++ b/src/quick/util/qquickpropertychanges.cpp
@@ -213,13 +213,15 @@ public:
     class ExpressionChange {
     public:
         ExpressionChange(const QString &_name,
+                         const QV4::CompiledData::Binding *_binding,
                          QQmlBinding::Identifier _id,
                          const QString& _expr,
                          const QUrl &_url,
                          int _line,
                          int _column)
-            : name(_name), id(_id), expression(_expr), url(_url), line(_line), column(_column) {}
+            : name(_name), binding(_binding), id(_id), expression(_expr), url(_url), line(_line), column(_column) {}
         QString name;
+        const QV4::CompiledData::Binding *binding;
         QQmlBinding::Identifier id;
         QString expression;
         QUrl url;
@@ -296,8 +298,7 @@ void QQuickPropertyChangesPrivate::decodeBinding(const QString &propertyPrefix,
         }
     }
 
-    if (binding->type == QV4::CompiledData::Binding::Type_Script) {
-        QString expression = binding->valueAsString(qmlUnit);
+    if (binding->type == QV4::CompiledData::Binding::Type_Script || binding->containsTranslations()) {
         QUrl url = QUrl();
         int line = -1;
         int column = -1;
@@ -309,16 +310,23 @@ void QQuickPropertyChangesPrivate::decodeBinding(const QString &propertyPrefix,
             column = ddata->columnNumber;
         }
 
-        expressions << ExpressionChange(propertyName, binding->value.compiledScriptIndex, expression, url, line, column);
+        QString expression;
+        QQmlBinding::Identifier id = QQmlBinding::Invalid;
+
+        if (!binding->containsTranslations()) {
+            expression = binding->valueAsString(qmlUnit);
+            id = binding->value.compiledScriptIndex;
+        }
+        expressions << ExpressionChange(propertyName, binding, id, expression, url, line, column);
         return;
     }
 
     QVariant var;
     switch (binding->type) {
     case QV4::CompiledData::Binding::Type_Script:
-        Q_UNREACHABLE();
     case QV4::CompiledData::Binding::Type_Translation:
     case QV4::CompiledData::Binding::Type_TranslationById:
+        Q_UNREACHABLE();
     case QV4::CompiledData::Binding::Type_String:
         var = binding->valueAsString(qmlUnit);
         break;
@@ -460,13 +468,14 @@ QQuickPropertyChanges::ActionList QQuickPropertyChanges::actions()
             QQmlContextData *context = QQmlContextData::get(qmlContext(this));
 
             QQmlBinding *newBinding = nullptr;
-            if (e.id != QQmlBinding::Invalid) {
+            if (e.binding && e.binding->containsTranslations()) {
+                newBinding = QQmlBinding::createTranslationBinding(d->compilationUnit, e.binding, object(), context);
+            } else if (e.id != QQmlBinding::Invalid) {
                 QV4::Scope scope(qmlEngine(this)->handle());
                 QV4::Scoped<QV4::QmlContext> qmlContext(scope, QV4::QmlContext::create(scope.engine->rootContext(), context, object()));
                 newBinding = QQmlBinding::create(&QQmlPropertyPrivate::get(prop)->core,
                                                  d->compilationUnit->runtimeFunctions.at(e.id), object(), context, qmlContext);
             }
-//            QQmlBinding *newBinding = e.id != QQmlBinding::Invalid ? QQmlBinding::createBinding(e.id, object(), qmlContext(this)) : 0;
             if (!newBinding)
                 newBinding = QQmlBinding::create(&QQmlPropertyPrivate::get(prop)->core,
                                                  e.expression, object(), context, e.url.toString(), e.line);
@@ -645,7 +654,7 @@ void QQuickPropertyChanges::changeExpression(const QString &name, const QString
     }
 
     // adding a new expression.
-    expressionIterator.insert(ExpressionEntry(name, QQmlBinding::Invalid, expression, QUrl(), -1, -1));
+    expressionIterator.insert(ExpressionEntry(name, nullptr, QQmlBinding::Invalid, expression, QUrl(), -1, -1));
 
     if (state() && state()->isStateActive()) {
         if (hadValue) {
diff --git a/tests/auto/qml/qqmltranslation/data/TranslationChangeBase.qml b/tests/auto/qml/qqmltranslation/data/TranslationChangeBase.qml
index c447c84987..294fff3284 100644
--- a/tests/auto/qml/qqmltranslation/data/TranslationChangeBase.qml
+++ b/tests/auto/qml/qqmltranslation/data/TranslationChangeBase.qml
@@ -1,5 +1,5 @@
-import QtQml 2.0
+import QtQuick 2.0
 
-QtObject {
+Item {
     property string baseProperty: qsTr("translate me");
 }
diff --git a/tests/auto/qml/qqmltranslation/data/translationChange.qml b/tests/auto/qml/qqmltranslation/data/translationChange.qml
index 23b87c2493..c48a482138 100644
--- a/tests/auto/qml/qqmltranslation/data/translationChange.qml
+++ b/tests/auto/qml/qqmltranslation/data/translationChange.qml
@@ -1,10 +1,24 @@
-import QtQml 2.0
+import QtQuick 2.0
 
 TranslationChangeBase {
+    id: root
+
     baseProperty: "do not translate"
     property string text1: qsTr("translate me")
     function weDoTranslations() {
         return qsTr("translate me")
     }
     property string text2: weDoTranslations()
+    property string text3
+
+    states: [
+        State {
+            name: "default"
+            when: 1 == 1
+            PropertyChanges {
+                target: root
+                text3: qsTr("translate me")
+            }
+        }
+    ]
 }
diff --git a/tests/auto/qml/qqmltranslation/tst_qqmltranslation.cpp b/tests/auto/qml/qqmltranslation/tst_qqmltranslation.cpp
index fc736cde1a..1c67ba5541 100644
--- a/tests/auto/qml/qqmltranslation/tst_qqmltranslation.cpp
+++ b/tests/auto/qml/qqmltranslation/tst_qqmltranslation.cpp
@@ -194,6 +194,7 @@ void tst_qqmltranslation::translationChange()
     QCOMPARE(object->property("baseProperty").toString(), QString::fromUtf8("do not translate"));
     QCOMPARE(object->property("text1").toString(), QString::fromUtf8("translate me"));
     QCOMPARE(object->property("text2").toString(), QString::fromUtf8("translate me"));
+    QCOMPARE(object->property("text3").toString(), QString::fromUtf8("translate me"));
 
     DummyTranslator translator;
     QCoreApplication::installTranslator(&translator);
@@ -204,6 +205,7 @@ void tst_qqmltranslation::translationChange()
     QCOMPARE(object->property("baseProperty").toString(), QString::fromUtf8("do not translate"));
     QCOMPARE(object->property("text1").toString(), QString::fromUtf8("xxx"));
     QCOMPARE(object->property("text2").toString(), QString::fromUtf8("xxx"));
+    QCOMPARE(object->property("text3").toString(), QString::fromUtf8("xxx"));
 
     QCoreApplication::removeTranslator(&translator);
 }