bug#81502: [PATCH] tests: chgrp: test --preserve-root within a chroot env

On 27/07/2026 04:03, zuohsh wrote:
> * tests/local.mk: reference the new test.
> * tests/chgrp/preserve-root.sh: the new file.
> ---

> +print_ver_ chgrp
> +require_root_

OK so you're proposing this as root
to support chroot, rather than have chgrp operate as root?
In that case I think chroot --userspec=... would be safer.

Also a general point is that chown and chgrp are essentially the same,
so it would be good to test both.
Actually we already have an existing
https://github.com/coreutils/coreutils/blob/master/tests/chown/preserve-root.sh
so it would be good to mention a quick summary of what extra this tests.

> +
> +# Create a safe chroot environment for testing
> +chroot_dir="$PWD/chroot_test"
> +mkdir -p "$chroot_dir"/{bin,lib,lib64,etc,dev,tmp} || framework_failure_
> +# Copy essential files for chroot to work
> +cp /bin/sh "$chroot_dir/bin/" 2>/dev/null || \
> +  cp /usr/bin/sh "$chroot_dir/bin/sh" 2>/dev/null || framework_failure_
> +
> +# Copy required libraries if any
> +ldd $chroot_dir/bin/sh 2>/dev/null | grep -o '/lib[^ ]*' | while read lib; do
> +  test -f "$lib" && cp "$lib" "$chroot_dir/lib/" 2>/dev/null || true
> +done
> +
> +pwd
> +# Copy chgrp binary to chroot
> +cp ${srcdir}/src/chgrp "$chroot_dir/bin/chgrp" || framework_failure_
> +
> +# Copy chgrp's required libraries
> +ldd $chroot_dir/bin/chgrp | grep -o '/lib[^ ]*' | while read lib; do
> +  test -f "$lib" && cp "$lib" "$chroot_dir/lib/" 2>/dev/null || true
> +  test -f "$lib" && cp "$lib" "$chroot_dir/lib64/" 2>/dev/null || true
> +done

Note the chroot setup we use in
https://github.com/coreutils/coreutils/blob/master/tests/nproc/nproc-quota.sh
where we use `command -v ...` to identify the binary,
and cp --parents to copy the dependencies.

> +
> +# Create minimal device nodes
> +mknod "$chroot_dir/dev/null" c 1 3 2>/dev/null || true
> +chmod 666 "$chroot_dir/dev/null" 2>/dev/null || true

Why the || true here?

> +
> +# Test 1: --preserve-root should refuse recursive operation on /
> +echo "=== Test 1: preserve-root on / ===" >&2
> +chroot "$chroot_dir" /bin/chgrp -R --preserve-root 1 / 2>out && fail=1
> +echo "=== Test 1 output ===" >&2
> +cat out >&2
> +echo "=== End Test 1 output ===" >&2
> +grep "it is dangerous to operate recursively.*'/'" out >/dev/null || fail=1
> +
> +# Test 2: --no-preserve-root should allow the operation
> +chroot "$chroot_dir" /bin/chgrp -R --no-preserve-root 1 / 2>out || true

and here?

thanks,
Padraig