Bug#816703: regression: "mv from to" now fails when both are the same file

[Pádraig Brady]

On 03/03/16 21:24, Marc Lehmann wrote:

Package: coreutils
Version: 8.25-2
Severity: normal

Dear Maintainer,

as an extension, coreutils supported moving one file to another, when both
refer to the same file.

This support has been lost after upgrading from 8.23-4 (stable) to
8.25-2. That is, in 8.25-2:

    # touch a; ln -f a b; mv a b
    mv: 'a' and 'b' are the same file

and both names still exist. While in 8.24-4, the "obvious" happens, i.e.
only "b" is left after the mv command.

It would be wonderful if this extension could somehow survive, as the
new behaviour is rather counter-intuitive (one expects that "mv a b", if
possible, makes b refer to a, and a is gone afterwards).

Thanks!

-- System Information:
Debian Release: 8.3
   APT prefers stable
   APT policy: (990, 'stable'), (500, 'unstable'), (500, 'testing'), (500, 
'oldstable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.1.18-040118-generic (SMP w/12 CPU cores)
Locale: LANG=C, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash
Init: systemd (via /run/systemd/system)

Versions of packages coreutils depends on:
ii  libacl1      2.2.52-2
ii  libattr1     1:2.4.47-2
ii  libc6        2.21-9
ii  libselinux1  2.4-3

coreutils recommends no packages.

coreutils suggests no packages.

This changed in v8.24 with the NEWS:

  mv no longer supports moving a file to a hardlink, instead issuing an error.
  The implementation was susceptible to races in the presence of multiple mv
  instances, which could result in both hardlinks being deleted.  Also on case
  insensitive file systems like HFS, mv would just remove a hardlinked 'file'
  if called like `mv file File`.  The feature was added in coreutils-5.0.1.