[pitivi] timeline/track.py: set operation state to null after removing transitions

[Edward Hervey <edwardrv src gnome org>]

commit f90d911e80fd6456f37d63083eb1246d1c7c2651
Author: Brandon Lewis <brandon_lewis alum berkeley edu>
Date:   Sat Mar 13 00:41:49 2010 -0800

    timeline/track.py: set operation state to null after removing transitions

 pitivi/timeline/track.py |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/pitivi/timeline/track.py b/pitivi/timeline/track.py
index 3b5ebfc..05f6094 100644
--- a/pitivi/timeline/track.py
+++ b/pitivi/timeline/track.py
@@ -781,6 +781,7 @@ class VideoTransition(Transition):
 
     def removeThyselfFromComposition(self, composition):
         composition.remove(self.operation)
+        self.operation.set_state(gst.STATE_NULL)
 
     def _updateOperationStart(self, start):
         self.operation.props.start = start
@@ -834,6 +835,8 @@ class AudioTransition(Transition):
     def removeThyselfFromComposition(self, composition):
         composition.remove(self.a_operation)
         composition.remove(self.b_operation)
+        self.a_operation.set_state(gst.STATE_NULL)
+        self.b_operation.set_state(gst.STATE_NULL)
 
     def _updateOperationStart(self, start):
         self.a_operation.props.start = start