Allow for garbage collection of types with errors in trimCache()

Change-Id: I821ea14f60871735bface4e2cf4e61fcb61b2784
Task-number: QTBUG-55567
Reviewed-by: Michael Brasser <michael.brasser@live.com>
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>

6 files changed, 58 insertions, 2 deletions

diff --git a/src/qml/qml/qqmltypeloader.cpp b/src/qml/qml/qqmltypeloader.cpp
index 01200fd881..6480420212 100644
--- a/src/qml/qml/qqmltypeloader.cpp
+++ b/src/qml/qml/qqmltypeloader.cpp
@@ -1961,8 +1961,10 @@ void QQmlTypeLoader::trimCache()
         QList<TypeCache::Iterator> unneededTypes;
         for (TypeCache::Iterator iter = m_typeCache.begin(), end = m_typeCache.end(); iter != end; ++iter)  {
             QQmlTypeData *typeData = iter.value();
-            if (typeData->m_compiledData && typeData->count() == 1
-                    && typeData->m_compiledData->count() == 1) {
+
+            const bool hasError = !typeData->m_compiledData && !typeData->m_errors.isEmpty();
+            const bool isNotReferenced = typeData->m_compiledData && typeData->m_compiledData->count() == 1;
+            if (typeData->count() == 1 && (hasError || isNotReferenced)) {
                 // There are no live objects of this type
                 unneededTypes.append(iter);
             }
diff --git a/tests/auto/qml/qqmltypeloader/data/MyComponent.qml b/tests/auto/qml/qqmltypeloader/data/MyComponent.qml
new file mode 100644
index 0000000000..a642518199
--- /dev/null
+++ b/tests/auto/qml/qqmltypeloader/data/MyComponent.qml
@@ -0,0 +1,11 @@
+import QtQuick 2.0
+
+Rectangle {
+    width: 100
+    height: 62
+
+    MyComponent3 {}
+
+    MyComponent2 {}
+}
+
diff --git a/tests/auto/qml/qqmltypeloader/data/MyComponent2.qml b/tests/auto/qml/qqmltypeloader/data/MyComponent2.qml
new file mode 100644
index 0000000000..02cf5cb5dd
--- /dev/null
+++ b/tests/auto/qml/qqmltypeloader/data/MyComponent2.qml
@@ -0,0 +1,7 @@
+import QtQuick 2.0
+
+Rectangle {
+    width: 100
+    height: 62
+}
+
diff --git a/tests/auto/qml/qqmltypeloader/data/MyComponent3.qml b/tests/auto/qml/qqmltypeloader/data/MyComponent3.qml
new file mode 100644
index 0000000000..ad5d569197
--- /dev/null
+++ b/tests/auto/qml/qqmltypeloader/data/MyComponent3.qml
@@ -0,0 +1,9 @@
+import QtQuick 2.0
+
+Rectangle {
+    width: 100
+    height: 62
+
+    MyComponent4 {}
+}
+
diff --git a/tests/auto/qml/qqmltypeloader/data/trim_cache2.qml b/tests/auto/qml/qqmltypeloader/data/trim_cache2.qml
new file mode 100644
index 0000000000..326a720a87
--- /dev/null
+++ b/tests/auto/qml/qqmltypeloader/data/trim_cache2.qml
@@ -0,0 +1,13 @@
+import QtQuick 2.0
+
+Item {
+    width: 400
+    height: 400
+
+    Component.onCompleted: {
+        var component = Qt.createComponent("MyComponent.qml")
+        if (component.status == Component.Error)
+            console.log(component.errorString())
+    }
+}
+
diff --git a/tests/auto/qml/qqmltypeloader/tst_qqmltypeloader.cpp b/tests/auto/qml/qqmltypeloader/tst_qqmltypeloader.cpp
index a1eaa0567f..8eb413e9f7 100644
--- a/tests/auto/qml/qqmltypeloader/tst_qqmltypeloader.cpp
+++ b/tests/auto/qml/qqmltypeloader/tst_qqmltypeloader.cpp
@@ -48,6 +48,7 @@ private slots:
     void testLoadComplete();
     void loadComponentSynchronously();
     void trimCache();
+    void trimCache2();
 };
 
 void tst_QQMLTypeLoader::testLoadComplete()
@@ -112,6 +113,19 @@ void tst_QQMLTypeLoader::trimCache()
     }
 }
 
+void tst_QQMLTypeLoader::trimCache2()
+{
+    QQuickView *window = new QQuickView();
+    window->setSource(testFileUrl("trim_cache2.qml"));
+    QQmlTypeLoader &loader = QQmlEnginePrivate::get(window->engine())->typeLoader;
+    // in theory if gc has already run this could be false
+    // QCOMPARE(loader.isTypeLoaded(testFileUrl("MyComponent2.qml")), true);
+    window->engine()->collectGarbage();
+    QTest::qWait(1);    // force event loop
+    window->engine()->trimComponentCache();
+    QCOMPARE(loader.isTypeLoaded(testFileUrl("MyComponent2.qml")), false);
+}
+
 QTEST_MAIN(tst_QQMLTypeLoader)
 
 #include "tst_qqmltypeloader.moc"