Tor crashes when "extendcircuit" (control) is given only a circuit ID
$ nc 127.0.0.1 1234
protocolinfo
250-PROTOCOLINFO 1
250-AUTH METHODS=HASHEDPASSWORD
250-VERSION Tor="0.2.5.10"
250 OK
authenticate "password"
250 OK
extendcircuit 0
250 EXTENDED 7
extendcircuit 7
<crash>
Jan 05 20:42:13.000 [notice] New control connection opened from 127.0.0.1.
Jan 05 20:42:22.000 [err] tor_assertion_failed_(): Bug: src/common/container.c:389: smartlist_split_string: Assertion str failed; aborting.
Jan 05 20:42:22.000 [err] Bug: Assertion str failed in smartlist_split_string at src/common/container.c:389. Stack trace:
Jan 05 20:42:22.000 [err] Bug: 0 tor.real 0x001f2f51 log_backtrace + 82
Jan 05 20:42:22.000 [err] Bug: 1 tor.real 0x0020217d tor_assertion_failed_ + 249
Jan 05 20:42:22.000 [err] Bug: 2 tor.real 0x001f965c smartlist_split_string + 182
Jan 05 20:42:22.000 [err] Bug: 3 tor.real 0x00128333 handle_control_extendcircuit + 876
Jan 05 20:42:22.000 [err] Bug: 4 tor.real 0x0012b927 connection_control_process_inbuf + 3477
Jan 05 20:42:22.000 [err] Bug: 5 tor.real 0x0010f009 connection_process_inbuf + 353
Jan 05 20:42:22.000 [err] Bug: 6 tor.real 0x0010c29c connection_handle_read_impl + 954
Jan 05 20:42:22.000 [err] Bug: 7 tor.real 0x0010c3e9 connection_handle_read + 50
Jan 05 20:42:22.000 [err] Bug: 8 tor.real 0x00175a09 conn_read_callback + 138
Jan 05 20:42:22.000 [err] Bug: 9 libevent-2.0.5.dylib 0x0044227b event_persist_closure + 605
Jan 05 20:42:22.000 [err] Bug: 10 libevent-2.0.5.dylib 0x00441db4 event_process_active_single_queue + 270
Jan 05 20:42:22.000 [err] Bug: 11 libevent-2.0.5.dylib 0x0044241a event_process_active + 104
Jan 05 20:42:22.000 [err] Bug: 12 libevent-2.0.5.dylib 0x00442a7f event_base_loop + 643
Jan 05 20:42:22.000 [err] Bug: 13 tor.real 0x00178a27 do_main_loop + 991
Jan 05 20:42:22.000 [err] Bug: 14 tor.real 0x0017cabd tor_main + 293
Jan 05 20:42:22.000 [err] Bug: 15 tor.real 0x000b059e main + 58
Jan 05 20:42:22.000 [err] Bug: 16 tor.real 0x000b0535 start + 53
Abort trap: 6