Merged in [13586] from rjsparks@nostrum.com:

    Workaround an issue with the schedule editor by ensuring no sessions remain scheduled in a room whose purpose has changed to something other than holding sessions (such as becoming unavailable).
 - Legacy-Id: 13589
Note: SVN reference [13586] has been migrated to Git commit d4acb1c

Author: levkowetz

ietf/meeting/ajax.py

@@ -205,6 +205,19 @@ def timeslot_updslot(request, meeting, slotid):
 
     slot.save()
 
+    # WORKAROUND: Right now, if there are sessions scheduled in this timeslot
+    # when it is marked unavailable (or any other value besides "session") they
+    # become unreachable from the editing screen. The session is listed in the
+    # "unscheduled" block incorrectly, and drag-dropping it onto the a new
+    # timeslot produces erroneous results. To avoid this, we will silently
+    # unschedule any sessions in the timeslot that has just been made
+    # unavailable.
+
+    if slot.type_id != 'session':
+        slot.sessionassignments.all().delete()
+
+    # ENDWORKAROUND
+
     # need to return the new object.
     dict1 = slot.json_dict(request.build_absolute_uri('/'))
     dict1['message'] = 'valid'