Does C99 specify that this structure would be 0 initialized by default, or is this line missing a = { 0 }? - https://github.com/rxi/sj.h/blob/5cb5df45c8c37fd8c2322026a11... - it reads to me like r->depth might be randomly initialized and equal to depth by random chance on the first iteration of the sj__discard_until loop