Subject: bug#9141: [PATCH 1/3] extensions: Enable extensions on MacOS X 10.5 and later.

From: Paul Eggert <[email-masked]>
Date: Sun, 24 Jul 2011 23:05:35 -0700

On 07/24/11 22:59, Voelker, Bernhard wrote:

>>  #ifndef _ALL_SOURCE
>>  # undef _ALL_SOURCE
>>  #endif
>> +/* Enable general extensions on MacOS X.  */
>> +#ifndef _DARWIN_C_SOURCE
>> +# undef _DARWIN_C_SOURCE
>> +#endif
> 
> maybe it's too early in the morning for me ... but isn't this a NOP:
> "if X is not defined, then undefine it"?

Later shell magic edits the file to define it.
In that sense, it's just like _ALL_SOURCE,
which already works.