the missing check did not affect the default profile, since it has
both _XOPEN_SOURCE and _BSD_SOURCE defined, but it did break programs
which explicitly define _BSD_SOURCE, causing it to be the only feature
test macro present.
#define MB_LEN_MAX 4
#if defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) \
- || defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE)
+ || defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
#define PIPE_BUF 4096
#define PAGESIZE PAGE_SIZE