Clean up QmlContext's and QmlExpression's when a context gets deleted

4 files changed, 49 insertions, 3 deletions

diff --git a/src/declarative/qml/qmlcontext.cpp b/src/declarative/qml/qmlcontext.cpp
index 16399bc..df5f90e 100644
--- a/src/declarative/qml/qmlcontext.cpp
+++ b/src/declarative/qml/qmlcontext.cpp
@@ -86,6 +86,10 @@ void QmlContextPrivate::destroyed(QObject *obj)
 void QmlContextPrivate::init()
 {
     Q_Q(QmlContext);
+
+    if (parent) 
+        parent->d_func()->childContexts.insert(q);
+
     //set scope chain
     QScriptEngine *scriptEngine = engine->scriptEngine();
     QScriptValue scopeObj =
@@ -232,7 +236,24 @@ QmlContext::QmlContext(QmlContext *parentContext, QObject *parent)
 QmlContext::~QmlContext()
 {
     Q_D(QmlContext);
-    for(int ii = 0; ii < d->contextObjects.count(); ++ii) {
+    if (d->parent) 
+        d->parent->d_func()->childContexts.remove(this);
+
+    for (QSet<QmlContext *>::ConstIterator iter = d->childContexts.begin();
+            iter != d->childContexts.end();
+            ++iter) {
+        (*iter)->d_func()->invalidateEngines();
+        (*iter)->d_func()->parent = 0;
+    }
+
+    for (QSet<QmlExpression *>::ConstIterator iter = 
+            d->childExpressions.begin();
+            iter != d->childExpressions.end();
+            ++iter) {
+        (*iter)->d->ctxt = 0;
+    }
+
+    for (int ii = 0; ii < d->contextObjects.count(); ++ii) {
         QObjectPrivate *p = QObjectPrivate::get(d->contextObjects.at(ii));
         QmlSimpleDeclarativeData *data = 
             static_cast<QmlSimpleDeclarativeData *>(p->declarativeData);
@@ -245,6 +266,17 @@ QmlContext::~QmlContext()
     d->contextObjects.clear();
 }
 
+void QmlContextPrivate::invalidateEngines()
+{
+    if (!engine)
+        return;
+    engine = 0;
+    for (QSet<QmlContext *>::ConstIterator iter = childContexts.begin();
+            iter != childContexts.end();
+            ++iter) {
+        (*iter)->d_func()->invalidateEngines();
+    }
+}
 
 /*!
     Return the context's QmlEngine, or 0 if the context has no QmlEngine or the
diff --git a/src/declarative/qml/qmlcontext_p.h b/src/declarative/qml/qmlcontext_p.h
index 9faa7b7..c265474 100644
--- a/src/declarative/qml/qmlcontext_p.h
+++ b/src/declarative/qml/qmlcontext_p.h
@@ -47,6 +47,7 @@
 #include <private/qmldeclarativedata_p.h>
 #include <qhash.h>
 #include <qscriptvalue.h>
+#include <QtCore/qset.h>
 
 QT_BEGIN_NAMESPACE
 class QmlContext;
@@ -87,6 +88,10 @@ public:
     };
     void addDefaultObject(QObject *, Priority);
 
+    void invalidateEngines();
+    QSet<QmlContext *> childContexts;
+    QSet<QmlExpression *> childExpressions;
+
     QmlSimpleDeclarativeData contextData;
     QObjectList contextObjects;
 };
diff --git a/src/declarative/qml/qmlengine.cpp b/src/declarative/qml/qmlengine.cpp
index fc209c6..c39a0d5 100644
--- a/src/declarative/qml/qmlengine.cpp
+++ b/src/declarative/qml/qmlengine.cpp
@@ -805,6 +805,8 @@ QmlExpression::QmlExpression(QmlContext *ctxt, void *expr,
     d->ctxt = ctxt;
     if(ctxt && ctxt->engine())
         d->id = ctxt->engine()->d_func()->getUniqueId();
+    if(ctxt)
+        ctxt->d_func()->childExpressions.insert(this);
     d->me = me;
 }
 
@@ -816,6 +818,8 @@ QmlExpression::QmlExpression(QmlContext *ctxt, const QString &expr,
     d->ctxt = ctxt;
     if(ctxt && ctxt->engine())
         d->id = ctxt->engine()->d_func()->getUniqueId();
+    if(ctxt)
+        ctxt->d_func()->childExpressions.insert(this);
     d->me = me;
 }
 
@@ -833,6 +837,8 @@ QmlExpression::QmlExpression(QmlContext *ctxt, const QString &expression,
     d->ctxt = ctxt;
     if(ctxt && ctxt->engine())
         d->id = ctxt->engine()->d_func()->getUniqueId();
+    if(ctxt)
+        ctxt->d_func()->childExpressions.insert(this);
     d->me = scope;
 }
 
@@ -841,6 +847,8 @@ QmlExpression::QmlExpression(QmlContext *ctxt, const QString &expression,
 */
 QmlExpression::~QmlExpression()
 {
+    if (d->ctxt)
+        d->ctxt->d_func()->childExpressions.remove(this);
     delete d; d = 0;
 }
 
@@ -850,7 +858,7 @@ QmlExpression::~QmlExpression()
 */
 QmlEngine *QmlExpression::engine() const
 {
-    return d->ctxt->engine();
+    return d->ctxt?d->ctxt->engine():0;
 }
 
 /*!
@@ -927,7 +935,7 @@ void BindExpressionProxy::changed()
 QVariant QmlExpression::value()
 {
     QVariant rv;
-    if (!d->ctxt || (!d->sse.isValid() && d->expression.isEmpty()))
+    if (!d->ctxt || !engine() || (!d->sse.isValid() && d->expression.isEmpty()))
         return rv;
 
 #ifdef Q_ENABLE_PERFORMANCE_LOG
diff --git a/src/declarative/qml/qmlexpression.h b/src/declarative/qml/qmlexpression.h
index bb6980a..2c6b1ad 100644
--- a/src/declarative/qml/qmlexpression.h
+++ b/src/declarative/qml/qmlexpression.h
@@ -87,6 +87,7 @@ protected:
 private:
     friend class BindExpressionProxy;
     friend class QmlDebugger;
+    friend class QmlContext;
     QmlExpressionPrivate *d;
 };