Author: Julia Lawall <julia@diku.dk> IW_ENCODE_MODE is 0xF000 and thus !erq->flags & IW_ENCODE_MODE is always 0. I assume that !(erq->flags & IW_ENCODE_MODE) was intended. The semantic patch that makes this change is as follows: (http://www.emn.fr/x-info/coccinelle/) // @@ expression E; constant C; @@ ( !E & !C | – !E & C + !(E & C) ) …