Fix QtQuick2 module unload support

This commit ensures that the value type providers installed by the
QtQuick2 QML module during initialization are uninstalled when the
plugin is unloaded.

It also fixes a bug in the type compiler so that it now works with
types from plugins which get unloaded and then reloaded.

Task-number: QTBUG-43004
Change-Id: I4b3fb75aae65dfbc5de9c88701ed82514087ab7d
Reviewed-by: Matthew Vogt <matthew.vogt@qinetic.com.au>

1 files changed, 45 insertions, 0 deletions

diff --git a/tests/auto/qml/qqmlenginecleanup/tst_qqmlenginecleanup.cpp b/tests/auto/qml/qqmlenginecleanup/tst_qqmlenginecleanup.cpp
index fcc3e6a0a9..c8fae624a7 100644
--- a/tests/auto/qml/qqmlenginecleanup/tst_qqmlenginecleanup.cpp
+++ b/tests/auto/qml/qqmlenginecleanup/tst_qqmlenginecleanup.cpp
@@ -46,6 +46,7 @@ public:
 
 private slots:
     void test_qmlClearTypeRegistrations();
+    void test_valueTypeProviderModule(); // QTBUG-43004
 };
 
 void tst_qqmlenginecleanup::test_qmlClearTypeRegistrations()
@@ -85,6 +86,50 @@ void tst_qqmlenginecleanup::test_qmlClearTypeRegistrations()
     delete component;
 }
 
+static void cleanState(QQmlEngine **e)
+{
+    delete *e;
+    qmlClearTypeRegistrations();
+    *e = new QQmlEngine;
+    QCoreApplication::sendPostedEvents(0, QEvent::DeferredDelete);
+    QCoreApplication::processEvents();
+}
+
+void tst_qqmlenginecleanup::test_valueTypeProviderModule()
+{
+    // this test ensures that a module which installs a value type
+    // provider can be reinitialized after multiple calls to
+    // qmlClearTypeRegistrations() without causing cycles in the
+    // value type provider list.
+    QQmlEngine *e = 0;
+    QUrl testFile1 = testFileUrl("testFile1.qml");
+    QUrl testFile2 = testFileUrl("testFile2.qml");
+    bool noCycles = false;
+    for (int i = 0; i < 20; ++i) {
+        cleanState(&e);
+        QQmlComponent c(e, this);
+        c.loadUrl(i % 2 == 0 ? testFile1 : testFile2); // this will hang if cycles exist.
+    }
+    delete e;
+    e = 0;
+    noCycles = true;
+    QVERIFY(noCycles);
+
+    // this test ensures that no crashes occur due to using
+    // a dangling QQmlType pointer in the type compiler
+    // which results from qmlClearTypeRegistrations()
+    QUrl testFile3 = testFileUrl("testFile3.qml");
+    bool noDangling = false;
+    for (int i = 0; i < 20; ++i) {
+        cleanState(&e);
+        QQmlComponent c(e, this);
+        c.loadUrl(i % 2 == 0 ? testFile1 : testFile3); // this will crash if dangling ptr exists.
+    }
+    delete e;
+    noDangling = true;
+    QVERIFY(noDangling);
+}
+
 QTEST_MAIN(tst_qqmlenginecleanup)
 
 #include "tst_qqmlenginecleanup.moc"