QQuickLoader: Do not incubate if the source arrives after setActive(false)

Otherwise we end up in the crazy place of active being false but item
being non-null and forces us to workaround within the apps.

Change-Id: I88c27c4b00ccec8b8e0c05a8e10b44fcabfc2e30
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
(cherry picked from commit e78c068700fa74ab3aca6a23ab2450563b1c3a5c)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

4 files changed, 46 insertions, 0 deletions

diff --git a/src/quick/items/qquickloader.cpp b/src/quick/items/qquickloader.cpp
index d2f083e295..88f8af81d2 100644
--- a/src/quick/items/qquickloader.cpp
+++ b/src/quick/items/qquickloader.cpp
@@ -737,6 +737,9 @@ void QQuickLoaderPrivate::_q_sourceLoaded()
         return;
     }
 
+    if (!active)
+        return;
+
     QQmlContext *creationContext = component->creationContext();
     if (!creationContext) creationContext = qmlContext(q);
     itemContext = new QQmlContext(creationContext);
diff --git a/tests/auto/quick/qquickloader/data/loader-async-race-rect.qml b/tests/auto/quick/qquickloader/data/loader-async-race-rect.qml
new file mode 100644
index 0000000000..a56dcea5ad
--- /dev/null
+++ b/tests/auto/quick/qquickloader/data/loader-async-race-rect.qml
@@ -0,0 +1,10 @@
+import QtQuick 2.15
+
+Rectangle {
+    anchors.fill: parent
+    color: "blue"
+    Item {
+        Item {
+        }
+    }
+}
diff --git a/tests/auto/quick/qquickloader/data/loader-async-race.qml b/tests/auto/quick/qquickloader/data/loader-async-race.qml
new file mode 100644
index 0000000000..8ba625c5c1
--- /dev/null
+++ b/tests/auto/quick/qquickloader/data/loader-async-race.qml
@@ -0,0 +1,14 @@
+import QtQuick 2.15
+
+Item {
+    id: root
+    Component.onCompleted: {
+        myloader.active = false
+    }
+    Loader {
+        id: myloader
+        anchors.fill: parent
+        asynchronous: true
+        source: "loader-async-race-rect.qml"
+    }
+}
diff --git a/tests/auto/quick/qquickloader/tst_qquickloader.cpp b/tests/auto/quick/qquickloader/tst_qquickloader.cpp
index 0f6c811adb..dddacbaa0b 100644
--- a/tests/auto/quick/qquickloader/tst_qquickloader.cpp
+++ b/tests/auto/quick/qquickloader/tst_qquickloader.cpp
@@ -132,6 +132,7 @@ private slots:
     void statusChangeOnlyEmittedOnce();
 
     void setSourceAndCheckStatus();
+    void asyncLoaderRace();
 };
 
 Q_DECLARE_METATYPE(QList<QQmlError>)
@@ -1496,6 +1497,24 @@ void tst_QQuickLoader::setSourceAndCheckStatus()
     QCOMPARE(loader->status(), QQuickLoader::Null);
 }
 
+void tst_QQuickLoader::asyncLoaderRace()
+{
+    QQmlApplicationEngine engine;
+    auto url = testFileUrl("loader-async-race.qml");
+    engine.load(url);
+    auto root = engine.rootObjects().at(0);
+    QVERIFY(root);
+
+    QQuickLoader *loader = root->findChild<QQuickLoader *>();
+    QCOMPARE(loader->active(), false);
+    QCOMPARE(loader->status(), QQuickLoader::Null);
+    QCOMPARE(loader->item(), nullptr);
+
+    QSignalSpy spy(loader, &QQuickLoader::itemChanged);
+    QVERIFY(!spy.wait(100));
+    QCOMPARE(loader->item(), nullptr);
+}
+
 QTEST_MAIN(tst_QQuickLoader)
 
 #include "tst_qquickloader.moc"