Stop using setSharable in the Java-style mutable iterators

First and foremost, the STL-style iterators don't do this. Those don't
provide a guarantee that the container won't get shared again while the
iterator is active.

Second, there's no protection against a second mutable iterator being
created and resetting the sharable flag back to true.

[ChangeLog][Important behavior changes] The mutable Java-style iterators
like QListMutableIterator and QHashMutableIterator no longer set the
parent container to unsharable mode. If you create a copy of the
container being iterated on after the iterator, any changes done with
the iterator might affect the copy too.

Discussed-on: http://lists.qt-project.org/pipermail/development/2014-February/015724.html
Change-Id: Iccfe411d5558c85ae459cff944215614c392388e
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@digia.com>

1 files changed, 2 insertions, 5 deletions

diff --git a/src/corelib/tools/qset.h b/src/corelib/tools/qset.h
index 992243def6..9682c97fec 100644
--- a/src/corelib/tools/qset.h
+++ b/src/corelib/tools/qset.h
@@ -356,12 +356,9 @@ class QMutableSetIterator
 public:
     inline QMutableSetIterator(QSet<T> &container)
         : c(&container)
-    { c->setSharable(false); i = c->begin(); n = c->end(); }
-    inline ~QMutableSetIterator()
-    { c->setSharable(true); }
+    { i = c->begin(); n = c->end(); }
     inline QMutableSetIterator &operator=(QSet<T> &container)
-    { c->setSharable(true); c = &container; c->setSharable(false);
-      i = c->begin(); n = c->end(); return *this; }
+    { c = &container; i = c->begin(); n = c->end(); return *this; }
     inline void toFront() { i = c->begin(); n = c->end(); }
     inline void toBack() { i = c->end(); n = i; }
     inline bool hasNext() const { return c->constEnd() != i; }