[syslinux] [PATCH] define _DEFAULT_SOURCE for glibc-2.20

[H. Peter Anvin]

>>
>> Actually, I tried to remove _BSD_SOURCE because I think it's unnecessary
>> flags.
>> However, I'm not sure whether the removing is correct or not.
>> Please look this mail thread[1].
>>
>> [1]: http://www.syslinux.org/archives/2014-September/022643.html
> 
> I mostly questioned it as a matter of "Why was it used in the first
> place?".  Commit 1769d57c94d7a965168b72b6fd8d48251710b452 at tag
> syslinux-2.00-pre8 (which I'd guess is actually from CVS import)
> states "Make the syslinux installer be setuid safe (we hope...)".
> 
> In lieu of HPA voicing up with a more definitive answer and in light
> of the manpage FEATURE_TEST_MACROS(7):
> 
> "To allow code that requires _BSD_SOURCE in glibc 2.19 and earlier and
> _DEFAULT_SOURCE in glibc 2.20 and later to compile without warnings,
> define both _BSD_SOURCE and _DEFAULT_SOURCE."[1]
> 
> I'd vote for this additional definition for now.
> 

I believe it was added for setreuid().  Note that support for running
syslinux setuid has long since been removed.

	-hpa