User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.7.0
I was looking at the newblock/killblock code today and I noticed that
killblock (better known as gunclone) is protected by BLOCK_SIGINT but
newblock is not. It's not clear to me whether this is really a bug, but
it seems safer to protect newblock also with BLOCK_SIGINT.