Merged in [14842] from rcross@amsl.com:

    Add check for deleted session when scheduling.  Fixes ietf-tools#2450.
 - Legacy-Id: 14847
Note: SVN reference [14842] has been migrated to Git commit 7211cf3

Author: levkowetz

ietf/meeting/ajax.py

@@ -455,6 +455,13 @@ def assignments_post(request, meeting, schedule):
                             status = 406,
                             content_type="application/json")
 
+    try:
+        Session.objects.get(pk=newvalues["session_id"])
+    except Session.DoesNotExist:
+        return HttpResponse(json.dumps({'error':'session has been deleted'}),
+                            status = 406,
+                            content_type="application/json")
+
     ss1 = SchedTimeSessAssignment(schedule = schedule,
                            session_id  = newvalues["session_id"],
                            timeslot_id = newvalues["timeslot_id"])

ietf/static/ietf/js/agenda/agenda_objects.js

@@ -482,6 +482,11 @@ ScheduledSlot.prototype.saveit = function() {
             session.placed(myss.timeslot);
         }
     });
+    saveit.fail(function(jqXHR, textStatus) {
+        var xhr = JSON.parse(jqXHR.responseText);
+        alert("ERROR: " + xhr.error + "\nThe schedule will now reload.");
+        location.reload(true);
+    });
 
     // return the promise, in case someone (tests!) needs to know when we are done.
     return saveit;