1 files changed, 50 insertions, 0 deletions
diff --git a/tests/cp/abuse.sh b/tests/cp/abuse.sh
new file mode 100755
index 0000000..4e65717
--- /dev/null
+++ b/tests/cp/abuse.sh
@@ -0,0 +1,50 @@
+#!/bin/sh
+# ensure that cp does not write through a just-copied symlink
+
+# Copyright (C) 2007-2022 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_ cp
+
+mkdir a b c || framework_failure_
+ln -s ../t a/1 || framework_failure_
+echo payload > b/1 || framework_failure_
+
+echo "cp: will not copy 'b/1' through just-created symlink 'c/1'" \
+  > exp || framework_failure_
+
+# Check both cases: a dangling symlink, and one pointing to a writable file.
+
+for i in dangling-dest existing-dest; do
+  test $i = existing-dest && echo i > t
+  test $i = dangling-dest && rm -f t
+
+  cp -dR a/1 b/1 c 2> out && fail=1
+
+  compare exp out || fail=1
+
+  # When the destination is a dangling symlink,
+  # ensure that cp does not create it.
+  test $i = dangling-dest \
+    && test -f t && fail=1
+
+  # When the destination symlink points to a writable file,
+  # ensure that cp does not change it.
+  test $i = existing-dest \
+    && case $(cat t) in i);; *) fail=1;; esac
+done
+
+Exit $fail