Mark function contexts as temporary

QTBUG-5690

6 files changed, 18 insertions, 5 deletions

diff --git a/src/declarative/qml/qmlbindingoptimizations.cpp b/src/declarative/qml/qmlbindingoptimizations.cpp
index d7105b2..868440e 100644
--- a/src/declarative/qml/qmlbindingoptimizations.cpp
+++ b/src/declarative/qml/qmlbindingoptimizations.cpp
@@ -145,8 +145,10 @@ void QmlOptimizedBindings::run(Binding *binding)
         qWarning("ERROR: Circular binding");
 
     QmlContext *context = QmlAbstractExpression::context();
-    if (!context)
+    if (!context) {
+        qWarning("QmlOptimizedBindings: Attempted to evaluate an expression in an invalid context");
         return;
+    }
     QmlContextPrivate *cp = QmlContextPrivate::get(context);
 
     if (binding->property & 0xFFFF0000) {
diff --git a/src/declarative/qml/qmlcontext.cpp b/src/declarative/qml/qmlcontext.cpp
index 4467cce..e063981 100644
--- a/src/declarative/qml/qmlcontext.cpp
+++ b/src/declarative/qml/qmlcontext.cpp
@@ -57,8 +57,8 @@
 QT_BEGIN_NAMESPACE
 
 QmlContextPrivate::QmlContextPrivate()
-: parent(0), engine(0), isInternal(false), propertyNames(0), notifyIndex(-1), 
-  highPriorityCount(0), imports(0), expressions(0), contextObjects(0),
+: parent(0), engine(0), isInternal(false), isTemporary(false), propertyNames(0), 
+  notifyIndex(-1), highPriorityCount(0), imports(0), expressions(0), contextObjects(0),
   idValues(0), idValueCount(0), optimizedBindings(0)
 {
 }
diff --git a/src/declarative/qml/qmlcontext_p.h b/src/declarative/qml/qmlcontext_p.h
index bc8c357..cb89474 100644
--- a/src/declarative/qml/qmlcontext_p.h
+++ b/src/declarative/qml/qmlcontext_p.h
@@ -86,7 +86,9 @@ public:
 
     QmlContext *parent;
     QmlEngine *engine;
+
     bool isInternal;
+    bool isTemporary;
 
     QmlIntegerCache *propertyNames;
     QList<QVariant> propertyValues;
diff --git a/src/declarative/qml/qmlengine.cpp b/src/declarative/qml/qmlengine.cpp
index 0e9b7c4..d5e3884 100644
--- a/src/declarative/qml/qmlengine.cpp
+++ b/src/declarative/qml/qmlengine.cpp
@@ -648,7 +648,10 @@ QmlContext *QmlEnginePrivate::getContext(QScriptContext *ctxt)
     QScriptValue scopeNode = QScriptDeclarativeClass::scopeChainValue(ctxt, -3);
     Q_ASSERT(scopeNode.isValid());
     Q_ASSERT(QScriptDeclarativeClass::scriptClass(scopeNode) == contextClass);
-    return contextClass->contextFromValue(scopeNode);
+    QmlContext *context = contextClass->contextFromValue(scopeNode);
+    while (context && QmlContextPrivate::get(context)->isTemporary)
+        context = context->parentContext();
+    return context;
 }
 
 QScriptValue QmlEnginePrivate::createComponent(QScriptContext *ctxt,
diff --git a/src/declarative/qml/qmlexpression.cpp b/src/declarative/qml/qmlexpression.cpp
index ab9f9ea..652c5f8 100644
--- a/src/declarative/qml/qmlexpression.cpp
+++ b/src/declarative/qml/qmlexpression.cpp
@@ -421,7 +421,12 @@ QVariant QmlExpressionPrivate::value(QObject *secondaryScope, bool *isUndefined)
     Q_Q(QmlExpression);
 
     QVariant rv;
-    if (!q->engine() || (!data->sse.isValid() && data->expression.isEmpty()))
+    if (!q->engine()) {
+        qWarning("QmlExpression: Attempted to evaluate an expression in an invalid context");
+        return rv;
+    }
+
+    if (!data->sse.isValid() && data->expression.isEmpty())
         return rv;
 
 #ifdef Q_ENABLE_PERFORMANCE_LOG
diff --git a/src/declarative/qml/qmlvmemetaobject.cpp b/src/declarative/qml/qmlvmemetaobject.cpp
index 8588eff..3b1f068 100644
--- a/src/declarative/qml/qmlvmemetaobject.cpp
+++ b/src/declarative/qml/qmlvmemetaobject.cpp
@@ -273,6 +273,7 @@ int QmlVMEMetaObject::metaCall(QMetaObject::Call c, int _id, void **a)
                     rv = expr.value();
                 } else {
                     QmlContext newCtxt(ctxt);
+                    QmlContextPrivate::get(&newCtxt)->isTemporary = true;
                     QMetaMethod m = method(_id);
                     QList<QByteArray> names = m.parameterNames(); 
                     for (int ii = 0; ii < names.count(); ++ii)