bug#27986: 26.0.50; 'rename-file' can rename files without confirmation

[Ken Brown]

On 8/13/2017 7:48 PM, Paul Eggert wrote:
> Getting back to Philipp's original bug report, Apple documentation says 
> macOS has a facility like the Linux renameat2 system call (i.e., it's 
> like 'renameat' except it can be told to fail if the destination already 
> exists). Attached is a proposed patch to use this facility, which means 
> that the case-insensitivity test would no longer need to be done in 
> macOS. If there's some way to implement renameat_noreplace on MS-Windows 
> we could get rid of the case-insensitivity test there too.

I think we still need the case-insensitivity test on Cygwin as well as 
on MS-Windows.

Ken