bug#15173: [PATCH] cp: with --link always use linkat() if available

[Pádraig Brady]

On 02/10/2014 02:29 AM, Paul Eggert wrote:
> Pádraig Brady wrote:
>> +#if ! defined HAVE_LINKAT
>>              && !(LINK_FOLLOWS_SYMLINKS && S_ISLNK (src_mode)
>> -                && x->dereference == DEREF_NEVER))
>> +                && x->dereference == DEREF_NEVER)
>> +#endif
> 
> Could you reword that sort of thing so as not to use the #if inside an 
> expression?  Something like this instead, perhaps, earlier in the code:
> 
>   #if !defined HAVE_LINKAT && LINK_FOLLOWS_SYMLINKS
>   # define LINKAT_FOLLOWS_SYMLINKS 1
>   #else
>   # define LINKAT_FOLLOWS_SYMLINKS 0
>   #endif

That's slightly confusing as linkat() emulation never
actually symlinks the referent.  I went for the more direct:

 #if defined HAVE_LINKAT || ! LINK_FOLLOWS_SYMLINKS
 # define CAN_HARDLINK_SYMLINKS 1
 #else
 # define CAN_HARDLINK_SYMLINKS 0
 #endif

Full patch is attached.

thanks,
Pádraig.

cp-linkat.patch
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