when ctrl C is pressed,it sometimes cause Segmentation fault[bug]

[yangguanglu]

^C20181225T182035 INFO [ucd] Stop signal detected (code: 2). 20181225T182035 INFO [ucd] Please wait while the server is stopping... 20181225T182035 INFO [http] Http Service Stopped. 20181225T182035 INFO [blockchain] Block [729] verify (1) txs and (1) inputs 20181225T182035 INFO [blockchain] Block [729] verified in (0) secs or (0) ms/input 20181225T182035 INFO [blockchain] Block [730] verify (1) txs and (1) inputs 20181225T182035 INFO [blockchain] Block [730] verified in (0) secs or (0) ms/input 20181225T182036 INFO [mgserver] Websocket Service Stopped. 20181225T182036 INFO [blockchain] Block [731] verify (1) txs and (1) inputs 20181225T182036 INFO [blockchain] Block [731] verified in (0) secs or (0) ms/input 20181225T182036 INFO [blockchain] Block [732] verify (1) txs and (1) inputs 20181225T182036 INFO [blockchain] Block [732] verified in (0) secs or (0) ms/input 20181225T182037 INFO [blockchain] Block [733] verify (1) txs and (1) inputs 20181225T182037 INFO [blockchain] Block [733] verified in (0) secs or (0) ms/input 20181225T182037 INFO [blockchain] Block [734] verify (1) txs and (1) inputs 20181225T182037 INFO [blockchain] Block [734] verified in (0) secs or (0) ms/input Segmentation fault: 11