I'm getting a segmentation fault. gdb says that it is this line:-
https://github.com/bitcoin/bitcoin/blob/bc121b0eb19713ec72002b5be03ba5ac35903a17/src/main.cpp#L457
Looking at the debug.log, this has happened twice in similar circumstances. Each time it's immediately after receivng a cmpctblock (which was requested) where the cmpctblock is for an alternative best tip that came in after the currently established tip.
It could be due to local changes to the code based off this point in master, so I am testing further to see if this is the case, but given the relative infrequency of this situation (obtaining compact blocks when there are two at the same height) it might take a while to track down the cause, so raising this issue in case it is not due to my changes.
96bb43d8262cb8b814cb68f0e10fe8a2fe141c05 and c37bbe778b25a4cc55eefdd1ab09c3a65ccf5e9a (two changes I made locally) might be to blame for this, so will test without these commits.