Subject: bug#14116: [PATCH] ln: allow to overwrite relative symlink

From: Eric Blake <[email-masked]>
Date: Mon, 08 Apr 2013 08:16:24 -0600

On 04/07/2013 01:20 AM, Linda Walsh wrote:
> 
> 
> Rémy Lefevre wrote:
> [>> Pádraig Brady wrote:
>>> Doing that though breaks `ln -sr target1 target2 dir` where dir is a symlink.
> ]
>> But could you provide me an example where the final component of the link
>> should be resolved ?
> ---
> 	What happens if 'dir' is a symlink, "-n" is used, and
> '/' (or '/.') is appended to "dir" in the above example?

According to POSIX, appending a trailing '/' requires that a name be
resolved as a directory (either an actual directory, or a symlink to a
directory).

> 
> 	Would that force 'dir' to be resolved, on the basis that
> '/' would be the final component.

'/' is never a final component (except for the root directory '/' where
it is the only component).  In POSIX parlance, a final component is
determined by stripping trailing slashes (except for the special case of
the root directory), then using the non-slash portion after the last
remaining slash.  However, the mere presence of a trailing slash does
affect resolution rules, in that the component being resolved has to be
a directory or a symlink to a directory.

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org