Make iteration over persistent values safer

This makes it safe to destruct persistents while
we are iterating over them.

Change-Id: I8797d0c553d3201859cdf03fb25df28836e55691
Reviewed-by: Simon Hausmann <simon.hausmann@theqtcompany.com>

1 files changed, 6 insertions, 2 deletions

diff --git a/src/qml/jsruntime/qv4persistent_p.h b/src/qml/jsruntime/qv4persistent_p.h
index 858734e9ed..67a76742d1 100644
--- a/src/qml/jsruntime/qv4persistent_p.h
+++ b/src/qml/jsruntime/qv4persistent_p.h
@@ -51,8 +51,10 @@ struct Q_QML_EXPORT PersistentValueStorage
     void mark(ExecutionEngine *e);
 
     struct Iterator {
-        Q_DECL_CONSTEXPR Iterator(void *p, int idx)
-            : p(p), index(idx) {}
+        Iterator(void *p, int idx);
+        Iterator(const Iterator &o);
+        Iterator & operator=(const Iterator &o);
+        ~Iterator();
         void *p;
         int index;
         Iterator &operator++();
@@ -68,6 +70,8 @@ struct Q_QML_EXPORT PersistentValueStorage
 
     ExecutionEngine *engine;
     void *firstPage;
+private:
+    static void freePage(void *page);
 };
 
 class Q_QML_EXPORT PersistentValue