add proper refcounting to XML SignalObserver. not refcounting caused crash upon opening Filter Editor dialog for the first time with a filtered object selected.

Fixed bugs:
  - https://launchpad.net/bugs/1328152

(bzr r13426)

1 files changed, 6 insertions, 2 deletions

diff --git a/src/xml/helper-observer.cpp b/src/xml/helper-observer.cpp
index c54dd8e74..e56ddc6f8 100644
--- a/src/xml/helper-observer.cpp
+++ b/src/xml/helper-observer.cpp
@@ -5,7 +5,7 @@ namespace XML {
 
 // Very simple observer that just emits a signal if anything happens to a node
 SignalObserver::SignalObserver()
-    : _oldsel(0)
+    : _oldsel(NULL)
 {}
 
 // Add this observer to the SPObject and remove it from any previous object
@@ -13,17 +13,21 @@ void SignalObserver::set(SPObject* o)
 {
   // XML Tree being used direcly in this function in the following code
   //   while it shouldn't be
+  // Pointer to object is stored, so refcounting should be increased/decreased
     if(_oldsel) {
         if (_oldsel->getRepr()) {
             _oldsel->getRepr()->removeObserver(*this);
         }
+        sp_object_unref(_oldsel);
+        _oldsel = NULL;
     }
     if(o) {
         if (o->getRepr()) {
             o->getRepr()->addObserver(*this);
+            sp_object_ref(o);
+            _oldsel = o;
         }
     }
-    _oldsel = o;
 }
 
 void SignalObserver::notifyChildAdded(XML::Node&, XML::Node&, XML::Node*)