removing in callback should be alright, we update the iterators

Change-Id: Iefaee20a603fa3f43a58107ea54e6e3f7a4d344f
since touching this: sprinkle in some nullptr

Change-Id: I8a229e020acddfda2e7c69fc7faf24d1c338c879
ugly preliminary hack for keeping ggc 4.6 happy

Change-Id: I41d605b5acbb54969d6b2cb68f06583983ee0d4b