From d1b0155d805ce51d8f155e648d1e9ad2edb95397 Mon Sep 17 00:00:00 2001 From: Jim Meyering Date: Thu, 5 Jan 2012 11:45:50 +0100 Subject: mv: allow moving symlink onto same-inode dest with >= 2 hard links Normally, mv detects a few subtle cases in which proceeding with a same-file rename would, with very high probability, cause data loss. Here, we have found a corner case in which one of these same-inode tests makes mv refuse to perform a useful operation. Permit that corner case. * src/copy.c (same_file_ok): Detect/exempt this case. * tests/mv/symlink-onto-hardlink: New test. * tests/Makefile.am (TESTS): Add it. * NEWS (Bug fixes): Mention it. Initially reported by: Matt McCutchen in http://bugs.gnu.org/6960. Raised again by Anders Kaseorg due to http://bugs.debian.org/654596. Improved-by: Paul Eggert. --- tests/Makefile.am | 1 + tests/mv/symlink-onto-hardlink | 41 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 42 insertions(+) create mode 100755 tests/mv/symlink-onto-hardlink (limited to 'tests') diff --git a/tests/Makefile.am b/tests/Makefile.am index 8b670fc40..a94aaa26f 100644 --- a/tests/Makefile.am +++ b/tests/Makefile.am @@ -491,6 +491,7 @@ TESTS = \ mv/part-symlink \ mv/partition-perm \ mv/perm-1 \ + mv/symlink-onto-hardlink \ mv/to-symlink \ mv/trailing-slash \ mv/update \ diff --git a/tests/mv/symlink-onto-hardlink b/tests/mv/symlink-onto-hardlink new file mode 100755 index 000000000..2dac48401 --- /dev/null +++ b/tests/mv/symlink-onto-hardlink @@ -0,0 +1,41 @@ +#!/bin/sh +# Ensure that mv works with a few symlink-onto-hard-link cases. + +# Copyright (C) 2012 Free Software Foundation, Inc. + +# This program is free software: you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation, either version 3 of the License, or +# (at your option) any later version. + +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. + +# You should have received a copy of the GNU General Public License +# along with this program. If not, see . + +. "${srcdir=.}/init.sh"; path_prepend_ ../src +print_ver_ mv + +touch f || framework_failure_ +ln f h || framework_failure_ +ln -s f s || framework_failure_ + +# Given two links f and h to some important content, and a symlink s to f, +# "mv s f" must fail because it might then be hard to find the link, h. +# "mv s l" may succeed because then, s (now "l") still points to f. +# Of course, if the symlink were being moved into a different destination +# directory, things would be very different, and, I suspect, implausible. + +echo "mv: 's' and 'f' are the same file" > exp || framework_failure_ +mv s f > out 2> err && fail=1 +compare /dev/null out || fail=1 +compare exp err || fail=1 + +mv s l > out 2> err || fail=1 +compare /dev/null out || fail=1 +compare /dev/null err || fail=1 + +Exit $fail -- cgit v1.2.3-70-g09d2