Detect binding loops.

Don't crash when a looping binding has been established. Instead, print
a warning and stop looping.

1 files changed, 37 insertions, 2 deletions

diff --git a/tests/auto/declarative/qmlbindengine/tst_qmlbindengine.cpp b/tests/auto/declarative/qmlbindengine/tst_qmlbindengine.cpp
index 0875690..ca840f4 100644
--- a/tests/auto/declarative/qmlbindengine/tst_qmlbindengine.cpp
+++ b/tests/auto/declarative/qmlbindengine/tst_qmlbindengine.cpp
@@ -7,7 +7,7 @@ class MyQmlObject : public QObject
     Q_OBJECT
     Q_PROPERTY(bool trueProperty READ trueProperty)
     Q_PROPERTY(bool falseProperty READ falseProperty)
-    Q_PROPERTY(QString stringProperty READ stringProperty WRITE setStringProperty)
+    Q_PROPERTY(QString stringProperty READ stringProperty WRITE setStringProperty NOTIFY stringChanged)
 public:
     MyQmlObject(): m_methodCalled(false), m_methodIntCalled(false) {}
 
@@ -15,7 +15,13 @@ public:
     bool falseProperty() const { return false; }
 
     QString stringProperty() const { return m_string; }
-    void setStringProperty(const QString &s) { m_string = s; }
+    void setStringProperty(const QString &s)
+    {
+        if (s == m_string)
+            return;
+        m_string = s;
+        emit stringChanged();
+    }
 
     bool methodCalled() const { return m_methodCalled; }
     bool methodIntCalled() const { return m_methodIntCalled; }
@@ -24,6 +30,7 @@ public:
 signals:
     void basicSignal();
     void argumentSignal(int a, QString b, qreal c);
+    void stringChanged();
 
 public slots:
     void method() { m_methodCalled = true; }
@@ -41,6 +48,22 @@ private:
 QML_DECLARE_TYPE(MyQmlObject);
 QML_DEFINE_TYPE(MyQmlObject,MyQmlObject);
 
+class MyQmlContainer : public QObject
+{
+    Q_OBJECT
+    Q_PROPERTY(QList<MyQmlContainer*>* children READ children)
+public:
+    MyQmlContainer() {}
+
+    QList<MyQmlContainer*> *children() { return &m_children; }
+
+private:
+    QList<MyQmlContainer*> m_children;
+};
+
+QML_DECLARE_TYPE(MyQmlContainer);
+QML_DEFINE_TYPE(MyQmlContainer,MyQmlContainer);
+
 class tst_qmlbindengine : public QObject
 {
     Q_OBJECT
@@ -51,6 +74,7 @@ private slots:
     void boolPropertiesEvaluateAsBool();
     void methods();
     void signalAssignment();
+    void bindingLoop();
 
 private:
     QmlEngine engine;
@@ -117,6 +141,17 @@ void tst_qmlbindengine::methods()
         QCOMPARE(object->methodIntCalled(), true);
     }
 }
+#include <QDebug>
+void tst_qmlbindengine::bindingLoop()
+{
+    QmlComponent component(&engine, "MyQmlContainer { children : [ "\
+                                    "MyQmlObject { id: Object1; stringProperty: \"hello\" + Object2.stringProperty }, "\
+                                    "MyQmlObject { id: Object2; stringProperty: \"hello\" + Object1.stringProperty } ] }");
+    //### ignoreMessage doesn't seem to work here
+    //QTest::ignoreMessage(QtWarningMsg, "QML MyQmlObject (unknown location): Binding loop detected for property \"stringProperty\"");
+    QObject *object = component.create();
+    QVERIFY(object != 0);
+}
 
 QTEST_MAIN(tst_qmlbindengine)