Deactivate buttons if parent was modified

issue1809
review265001

tryton/common/button.py

@@ -37,3 +37,9 @@ class Button(gtk.Button):
             self.show()
         self.set_sensitive(not states.get('readonly', False))
         self._set_icon(states.get('icon', self.attrs.get('icon')))
+        parent = record.parent if record else None
+        while parent:
+            if parent.modified:
+                self.set_sensitive(False)
+                break
+            parent = parent.parent