Double mark-for-close when connection_ap_handshake_rewrite_and_attach rejects a stream

When I attempted to connect to http://duskgytldkxiuqc$.onion/ (using usewithtor w3m; I don't know whether Firefox would try to connect to that hostname) using my feature2553-v2 branch ( git://git.torproject.org/rransom/tor.git feature2553-v2 ) (compiled with --enable-bufferevents), Tor produced the following warning message:

Jun 15 02:41:53.000 [warn] Invalid onion hostname [scrubbed]; rejecting
Jun 15 02:41:53.000 [warn] Bug: Duplicate call to connection_mark_for_close at connection.c:2956 (first at connection_edge.c:1702)

connection.c:2956 is in connection_handle_read_cb; connection_edge.c:1702 is in connection_ap_handshake_rewrite_and_attach.