Auto merge of #378 - thomaslee:tom_fix_kfreebsd, r=badboy
Auto merge of #378 - thomaslee:tom_fix_kfreebsd, r=badboy

Fix strerror_r on some esoteric platforms

Defining _XOPEN_SOURCE=1 causes strange behavior on Debian kfreebsd archs -- i.e. the GNU userspace with FreeBSD kernel -- when _GNU_SOURCE is not defined (the default).

Not sure I fully understand the bizarre semantics, but it seems to use the XSI-compliant interface (int strerror_r(int, char*, size_t)) but the GNU implementation (char *strerror_r(int, char*, size_t)) such that strerror_r returns 32-bits of a 64-bit char * on x86_64 kfreebsd. We would expect strerror_r to return zero when using the XSI-compliant strerror_r implementation or a 64-bit char* when using the GNU version. Instead, we get something in between!

Unless I'm missing something, being more explicit about what version of _XOPEN_SOURCE we want seems to be the prudent thing to do here -- and if folks want the GNU implementation of strerror_r for some reason they can always -D_GNU_SOURCE explicitly.

jinguoli/hiredis,owent-contrib/hiredis,jinguoli/hiredis,thomaslee/hiredis,jinguoli/hiredis,redis/hiredis,charsyam/hiredis,charsyam/hiredis,redis/hiredis,thomaslee/hiredis,owent-contrib/hiredis,redis/hiredis