1 files changed, 46 insertions, 0 deletions
diff --git a/tests/mv/atomic.sh b/tests/mv/atomic.sh
new file mode 100755
index 0000000..1b1d357
--- /dev/null
+++ b/tests/mv/atomic.sh
@@ -0,0 +1,46 @@
+#!/bin/sh
+# ensure that mv doesn't first unlink its destination in one particular case
+
+# Copyright (C) 2006-2022 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 <https://www.gnu.org/licenses/>.
+
+. "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
+print_ver_ mv
+require_strace_ unlink
+
+# Before the fix, mv would unnecessarily unlink the destination symlink:
+#   $ rm -rf s[12]; ln -s / s1; ln -s /tmp s2
+#   $ strace -qe unlink /bin/mv -T s1 s2
+#   unlink("s2") = 0
+#
+# With the fix, it doesn't call unlink:
+#   $ rm -rf s[12]; ln -s / s1; ln -s /tmp s2
+#   $ strace -qe unlink ./mv -T s1 s2
+#   $
+
+ln -s t1 s1 || framework_failure_
+ln -s t2 s2 || framework_failure_
+
+
+strace -qe unlink mv -T s1 s2 > out 2>&1 || fail=1
+$EGREP 'unlink.*"s1"' out && fail=1
+
+# Ensure that the source, s1, is gone.
+ls -dl s1 > /dev/null 2>&1 && fail=1
+
+# Ensure that the destination, s2, contains the link from s1.
+test "$(readlink s2)" = t1 || fail=1
+
+Exit $fail