QQmlIRLoader: Restore inline components correctly

Whether a component is an inline component is not only stored in the
flags, but also in the isInlineComponent member.
Ideally, this should be unified and the member removed, but for now we
just restore the value correctly.
Adjusted tst_qmlcachegen::initTestCase so that we testFile and
testFileUrl are actually usable in the test.

Fixes: QTBUG-84237
Pick-to: 5.15
Change-Id: I759cd6b8914b186b9e5c8118863fc8d0580d21af
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

src/qml/qml/qqmlirloader.cpp

@@ -95,6 +95,7 @@ QmlIR::Object *QQmlIRLoader::loadObject(const QV4::CompiledData::Object *seriali
 
     object->indexOfDefaultPropertyOrAlias = serializedObject->indexOfDefaultPropertyOrAlias;
     object->defaultPropertyIsAlias = serializedObject->defaultPropertyIsAlias;
+    object->isInlineComponent = serializedObject->flags & QV4::CompiledData::Object::IsInlineComponentRoot;
     object->flags = serializedObject->flags;
     object->id = serializedObject->id;
     object->location = serializedObject->location;

tests/auto/qml/qmlcachegen/data/inlineComponentWithId.qml

@@ -0,0 +1,10 @@
+import QtQuick 2.15
+
+Item {
+  component Test: Item {
+    id: test
+    property int t: 42
+    Component.onCompleted: console.info(test.t)
+  }
+  Test {}
+}

tests/auto/qml/qmlcachegen/tst_qmlcachegen.cpp

@@ -76,6 +76,7 @@ private slots:
     void reproducibleCache();
 
     void parameterAdjustment();
+    void inlineComponent();
 };
 
 // A wrapper around QQmlComponent to ensure the temporary reference counts
@@ -129,6 +130,7 @@ void tst_qmlcachegen::initTestCase()
     if (!cacheDir.isEmpty())
         //QDir(cacheDir).removeRecursively();
         qDebug() << cacheDir;
+    QQmlDataTest::initTestCase();
 }
 
 void tst_qmlcachegen::loadGeneratedFile()
@@ -690,6 +692,18 @@ void tst_qmlcachegen::parameterAdjustment()
     QVERIFY(!obj.isNull()); // Doesn't crash
 }
 
+
+void tst_qmlcachegen::inlineComponent()
+{
+    bool ok = generateCache(testFile("inlineComponentWithId.qml"));
+    QVERIFY(ok);
+    QQmlEngine engine;
+    CleanlyLoadingComponent component(&engine, testFileUrl("inlineComponentWithId.qml"));
+    QTest::ignoreMessage(QtMsgType::QtInfoMsg, "42");
+    QScopedPointer<QObject> obj(component.create());
+    QVERIFY(!obj.isNull());
+}
+
 QTEST_GUILESS_MAIN(tst_qmlcachegen)
 
 #include "tst_qmlcachegen.moc"