Re: RFC: allow empty symlink targets

On 05/15/2013 03:40 PM, Eric Blake wrote:

On 05/15/2013 06:38 AM, Pádraig Brady wrote:

quoted

On 01/17/2013 04:22 PM, Pádraig Brady wrote:

quoted

On 01/17/2013 01:03 PM, Pádraig Brady wrote:

quoted

The discussion leading to this is at http://bugs.gnu.org/13447
In summary other systems allow an empty target for a symlink,
and POSIX specifies that it should be allowed?

In relation to this, Eric Blake said:

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In today's Austin Group meeting, I was tasked to open a new bug that
would state specifically how the empty symlink is resolved; the intent
is to allow both Solaris behavior (current directory) and BSD behavior
(ENOENT).  Meanwhile, everyone was in agreement that the Linux kernel
has a bug for rejecting the creation of an empty symlink, but once that
bug is fixed, then Linux can choose either Solaris or BSD behavior for
how to resolve such a symlink.

It will probably be a bug report similar to this one, which regarded how
to handle a symlink containing just slashes:
http://austingroupbugs.net/view.php?id=541

Following up from http://austingroupbugs.net/view.php?id=649
It seems POSIX will now allow the current Linux behavior of returning ENOENT,

Huh?  Linux currently doesn't allow the creation of an empty symlink.
That link mentions the current BSD behavior of returning ENOENT when
resolving such a symlink (that is, what stat() does when chasing through
an empty symlink, provided such a symlink is first created).

Ah OK. The standards are hard enough to interpret,
never mind the comments discussing the standards :)
Not helping was that symlink() returns ENOENT in this case too.

quoted

or the Solaris behavior of allowing empty symlink targets.

The point made in that bug report is that Linux is buggy for not
allowing symlink() to create an empty symlink in the first place; once
you allow the creation of an empty symlink, then how to handle such a
symlink in stat() is up to you whether to copy Solaris' or BSD's example.

OK cool, that make more sense to me.

Adding in a couple more recipients to garner interest...

thanks,
Pádraig.