[pitivi] undo: Do not take into account ignored properties in the element

[Thibault Saunier <tsaunier src gnome org>]

commit 31d61b0d921734b7a58b7de2d970f170696fecb5
Author: Thibault Saunier <tsaunier gnome org>
Date:   Mon Jun 20 12:53:07 2016 -0400

    undo: Do not take into account ignored properties in the element
    
    Reviewed-by: Alex Băluț <alexandru balut gmail com>
    Differential Revision: https://phabricator.freedesktop.org/D1098

 pitivi/undo/timeline.py |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/pitivi/undo/timeline.py b/pitivi/undo/timeline.py
index 922f928..1d4e1c5 100644
--- a/pitivi/undo/timeline.py
+++ b/pitivi/undo/timeline.py
@@ -103,6 +103,9 @@ class TimelineElementObserver(Loggable):
 
     def _property_changed_cb(self, ges_timeline_element, unused_gst_element, pspec):
         prop_name = child_property_name(pspec)
+        if pspec.name in PROPS_TO_IGNORE:
+            return
+
         if ges_timeline_element.get_control_binding(prop_name):
             self.debug("Property %s controlled", prop_name)
             return